‘And now they have taken over’: hobbyist and professional archaeologist encounters with the material heritage of the First World War in western Belgium

ABSTRACT Since almost immediately after the fighting ended, the First World War (WWI) sites of conflict in Western Flanders, Belgium, have attracted attention from visitors and collectors. Heritage management questions came to the fore especially in the run-up to WWI’s centenary years (2014–2018), and professional archaeologists representing the authorities in Flanders had already begun to take a greater interest in the war’s archaeological remains. The activities of hobbyist amateurs, particularly metal detectorists, came under greater scrutiny. In this article, we explore the perspectives of local hobbyist enthusiasts and heritage professionals in the context of changing attitudes towards and values associated with the material heritage of the WWI in Western Flanders. We reflect upon the tensions that emerge when different interest groups clash, the disagreements between professional and amateur interests, and also upon the particular context of conflict heritage when there are numerous interests and stakeholders involved.


Introduction
In this paper, we track the transition, across the first decades of the twenty-first century, from amateur interventions with First World War (WWI) archaeology in Western Flanders as conducted in a local context, to a professionalised regime controlled by a remote administration. We conceptualise this transition in terms of three dimensions of power in relation to archaeological heritage: • Stewardship over this heritage, in the sense of which stakeholders and communities are allowed to access, make decisions about and manage sites and material culture connected to WWI. • Control of the ethical norms associated with it, for example how actors are expected to deal with certain problematic categories of discovery such as unexploded ordnance or human remains, and which principles are followed or privileged in this context. • Authority, namely, who is publicly recognised as expert and therefore having rights to work with WWI heritage, and who determines the narrative about the heritage that is presented to the public. discipline itself (the latter both arguably relating to control and authority) (e.g. Ireland and Schofield 2015, 2). As heritage management authorities took more interest in the material remains of WWI in Flanders, we focus in particular on the hobbyist actions of a group of amateur enthusiasts known as 'De Diggers', as well as the transforming attitudes towards them and other non-professionals from heritage managers and local government officials. Our case study contributes to the wider discussion of how public engagement with archaeological heritage is managed and controlled by specialists, and the connected issue of how amateur enthusiasts are viewed and understood, both by the wider public and by heritage professionals.
The current archaeological heritage management regime in many European countries has been that envisioned by the Council of Europe's Valletta Convention (1992): a routinised procedure, in which bureaucracy and regulation at the (supra-)regional and state level of government, and professional -often commercial -excavation units are the near-exclusive players. As well as marginalising the role of academic archaeologists in favour of heritage managers (Willems 2007, 58), it has often also complicated the participation of non-professional archaeological enthusiasts. The current archaeological regime in Flanders has its roots in the regionalisation of archaeological and cultural heritage. Consequently, a Flemish heritage agency (nowadays known as Flanders Heritage Agency) was founded in 1991. A second foundation is the Archaeology Decree of 1993, which operationalised much of the Valletta Convention, including the basic principles of preferred in-situ preservation, professionalisation, and developer-financed, threat-based fieldwork. One effect of this bureaucratisation and regulation of heritage management was a formalisation and circumscription of Flemish archaeological practice (Plets 2016). This regime of professional, developmentled archaeology was gradually installed, as Flanders Heritage Agency itself evolved from a scientific institute often involved in fieldwork, to a more administrative body overseeing the activities of numerous, mostly commercial excavators.
The split between so-called amateur, avocational or non-professional archaeologists and professional archaeologists has been characterised as becoming more divided over time, as archaeology became more professionalised (Henson 2014, 733). Yet, the origins of archaeological practice itself is situated in antiquarian, hobbyist pursuits, including periods when there was little division in status between avocational or amateur enthusiasts and paid professionals (Taylor 1995, 505), through to a later apparent dismissive attitude towards non-professionals. In more recent times, the division between professional and amateur has continued to draw debate, and while critiques of power exist (e.g. Smith 2006), in other cases the barriers have sometimes blurred. The hobby of metal detecting is particularly emotive to some, with arguments that these non-archaeologists practice their hobby with a sub-standard approach that contributes to the loss of archaeological knowledge (Gerstenblith 2013). At the same time, others have noted that metal detectorists can adopt 'the highest professional standards' (Dobat and Jensen 2016, 70), while not working as 'professionals' in the strictest sense of receiving salary for their efforts. Nonetheless, the divisions between the authority of the professional and the potentially alternative perspectives of the nonprofessional, continue to be a focal point of heritage studies, with debates around the so-called 'authorised heritage discourse' (Smith 2006) -the expert-accepted version of heritage and its meanings -continuing to be a cornerstone of critical heritage debates.
Professional archaeology has at times defined itself in contrast to amateur archaeological interests, despite the origins of archaeology within the realm of amateur enthusiasts. At the same time, interests in public archaeology, as well as the undeniable knowledge held by such amateurswhich sometimes differs significantly from that of professionals (e.g. Christenson 2013) -necessitate the acknowledgement of non-professional archaeological knowledge production. Among nonprofessional interests wishing to engage with archaeological heritage are those hobbyists that specifically look to retrieve artefacts. As a part of the spectrum of non-professionals engaging with archaeological heritage, metal detectorists in particular have met with criticism from professional archaeologists (discussed in Thomas and Pitblado 2020), while there is at the same time increasing realisation of the potential of metal-detected finds for contributing to archaeological knowledge if recorded properly, necessitating a greater engagement between these particular 'amateurs' and professionals (e.g. Dobat et al. 2020).
The complicated nature of the different practices of object retrieval from sites specifically connected to WWI in Flanders are variously understood as looting, or souvenir-or trophy hunting (Dendooven 2009, 68). Following a description of the methodology we employed, we present the ways in which archaeological interest evolved in Flanders -from a primarily amateur interest to the legislated preserve of heritage authorities. We then focus on the Diggers within the context of how attitudes from heritage authorities, including museums and archaeologists, changed towards them in the early twenty-first century. We then analyse how these attitudes reveal tensions and conflicts in how stewardship, control and authority are perceived in relation to WWI heritage in Flanders. Finally, we discuss these conflicts in relation to heritage management in general and how public participation with archaeology manifests following the assertion of professional archaeological authority.

Methodology
While there are some news articles and occasional correspondence records, the documentation for non-professional encounters with material culture in Flanders is generally only ephemeral from the period prior to the internet becoming mainstream, making interviews with those who remember and/or were active in these earlier periods (in our case, the 1980s and earlier 1990s) essential. Therefore, we have focused our data collection primarily on interviews, and two particular incidents that received press coverage.
We interviewed a total of nine interviewees, one woman and eight men, over a two-week period in April 2016. These were identified due to their connections to WWI sites in Flanders, either as archaeologists working in the region, amateur or professional researchers, or as hobbyist enthusiasts (including but not limited to metal detectorists); all resident in West Flanders. Table 1 indicates the dates on which the interviews took place, as well as the gender and status regarding cultural heritage (professional or hobbyist) of each interviewee. Interviewees all gave written consent to their interviews being recorded, and all are anonymised in this article. They are all aware that the data from their interviews are intended to assist in academic research. Given the relatively small and close-knit nature of both non-professional WWI enthusiasts and the professional archaeological community, it is not possible to give more details about interviewees' individual backgrounds without risking revealing their identities. Most of the interviews took place in English, but in one case some of the interview was conducted in English and Dutch, with Deckers acting as interpreter for Thomas. A university student, who signed a confidentiality agreement, transcribed the interviews. Following general analysis, we selected the sections most relevant to our research and categorised them under particular themes to help us perceive particular trends and points that came up across the interviews. We, therefore, engaged in a form of content analysis (Krippendorff 2018) in which the transcripts of the interviews were read over and then coded based on the key themes that appeared to emerge. From this, we identified, in particular, the themes of stewardship, control, and authority, which interviewees referenced in different ways. Examples from the interviews are used to illustrate this within the paper. Deckers additionally analysed press items to reconstruct the factual background and public perception of the events discussed during the interviews. A dataset of 122 press releases and articles, published between 1998 and 2009 in national (Flemish) and regional newspapers and magazines and relating to 82 distinct events or reports, was compiled using the Belgian press database Gopress (www.gopress.be) (Figure 1).
Relevant items were selected through the search terms 'Diggers', 'metaaldetectie' (en: metal detecting) and 'Wereldoorlog' (en: World War), as well as key individuals' names. The press dataset consists of short news items as well as longer journalistic pieces and interviews with numerous protagonists. It demonstrates the substantial, national interest that WWI archaeology and the issues surrounding the Diggers' activities aroused at certain moments. Furthermore, together with scholarly publications and other sources cited throughout this article, the press coverage allowed to reconstruct a factual timeline of the controversies involving the Diggers, providing a historical framework for the interviews. The press coverage both objectively reports on institutional developments and, through regional coverage and numerous interviews and personal statements, reveals the impact of these developments on local society and individuals. As such, it is well suited to examine the interests at stake when power in heritage starts to shift. These interests can be fruitfully explored through the threefold lens of stewardship, control and authority.

The development of archaeological interest in Flanders' WWI heritage
Professional archaeological interest did not focus on WWI heritage on the Western Front until relatively lately, and much later than the amateur interest that had already developed (Saunders 2007;van Hollebeeke, Stichelbaut, and Bourgeois 2014, 702;Pollard and Banks 2007, iii). Some archaeologists saw the period as too recent to be appropriate for archaeological research Figure 1. Graph showing the chronological distribution of Belgian press items from 1998 to 2009, concerning the Diggers' activities (collected from Gopress.be, n = 122). (Stichelbaut et al. 2018, 19). The first professional archaeologists to take an interest in this conflict heritage were not local Belgian or French archaeologists but from the UK, some with an explicit focus on the British experience in the war (e.g. Tarlow 1997). Early major projects specifically covering WWI included the Ocean Villas Project, which took place around the turn of the millennium at Auchonvillers in the French section of the Western Front. The archaeological investigation, involving primarily British archaeologists, owed much to the British owner of the 'Ocean Villas' guesthouse, herself driven by 'a strong personal commitment to the commemoration and interpretation of the war', as well as touristic considerations (Price 2004, 182).
In Flanders, Belgian archaeologists have relatively recently taken interest in WWI archaeology. Commentators identify archaeological investigations in 2002, associated with the planned (and later largely abandoned) extension of the A19 road, as the first significant work by Flemish archaeologists on WWI heritage (de Meyer and Pype 2004;Dewilde et al. 2004;Saunders 2007, 155-161;Dewilde 2010;van Hollebeeke, Stichelbaut, and Bourgeois 2014, 705). The excavation results, carried out ahead of the planned road extension, were considered important enough that the extension's route was altered to avoid unnecessary damage to WWI remains. Some have seen this change of plans as 'a political acknowledgement of the importance of the First World War heritage in Flanders' (Dewilde and Saunders 2009, 257). There have also been innovative developments utilising WWIera aerial photographs, with millions of them available for archaeological investigation (Stichelbaut et al. 2017).
Others have noted the activities of metal detectorists and collectors as a destructive threat to often as yet unrecorded material remains (e.g. Price 2004, 181;Pollard and Banks 2007, xi;Stichelbaut et al. 2018, 18 -but see Saunders 2007, 139-144 for a more elaborate and positive discussion of their role). Yet this non-professional, hobbyist interest in WWI began somewhat before professional and academic interest developed. Perhaps most active in this regard, and certainly the best-known group locally in Flanders, has been a small collective of metal detectorists and other amateur enthusiasts, the 'Diggers'; local men, who took an interest in exploring the region's WWI heritage from the late 1980s, applying their own research and technology as they went.
A collective of about 12 enthusiasts, all male, the Diggers used metal detectors and other tools to search WWI battle sites. Their name came about in a way by accident. According to one former member, the name stuck after someone, unrelated to the group, made a comment about their activities, noting, 'Oh, the diggers are back again' (FL5a, translated by Deckers). As the press record indicates, over the years they conducted numerous excavations, clearing ordnance ahead of building work, salvaging the remains of over 200 soldiers, collaborating with several regional museums including the In Flanders Fields Museum, and gaining the praise of experts and local politicians. Over the course of less than a decade, they lost this position of prominence, and are now largely sidelined as pioneers of WWI archaeology in Flanders.

'Headlines and missed opportunities': the decline of the Diggers
The Diggers' decline as a central actor in WWI archaeology in Western Flanders centres around two episodes receiving attention from national and, occasionally, international media, between 1998 and 2009 ( Figure 1). The first instance was the controversy surrounding a documentary that British television channel ITV aired in November 2000, titled 'Battlefield Scavengers'. One interviewee suggested that it came about due to the production company's desire to create a controversial depiction of hobbyists, also revealing the Diggers' (understandable) objection at being assigned this title as well as the wish to disassociate their own actions from it: 'Their mission was to find scavengers and they hadn't found any, so they had a brilliant idea of naming us "Scavengers" . . . '(FL1).
However, the documentary, and subsequent articles in British tabloids (Saunders 2007, 13-15; also see a personal account by one of the Diggers on their website, http://users.telenet.be/aurel. sercu/N/Ezine/aasgieren-engels.htm), alleged that the Diggers were excavating human remains disrespectfully and without supervision, and that they were removing regimental insignia and dog tags. These allegations were serious enough for the British government to request a formal explanation. In response, Belgian authorities, including the Foreign and Interior Ministries and the Flanders Heritage Agency (then called Instituut voor het Archeologisch Patrimonium, IAP) as well as the Commonwealth War Graves Commission, repudiated the claims as false (P.S.P 2000;De Stoop 2000), even though the head of IAP expressed some concerns in the British press (Tweedie 2000). One archaeologist involved in the earliest professional WWI fieldwork in Flanders later described the period of amateur archaeology as one of 'headlines on the one hand, missed opportunities on the other' (Dewilde 2013, 5, translation by Deckers). By the end of the month, ITV published a correcting statement (Galle 2000), and during the following year formal complaints by the Diggers concerning British press oversight were ruled in the Diggers' favour (Belga 2001a).
Despite exoneration for the Diggers, it proved a turning point. It revealed the high stakes involved in WWI heritage, both locally (with Ieper locals commenting in the press about potential reputation damage to the town - Beel 2000), and at Flanders region and Belgian state levels. In August 2001, it was reported that the federal Ministry of the Interior would draft guidelines for increased oversight of the battlefields, in collaboration with the Heritage Agency and the police (Belga 2001b). Thus, a first step was taken in the transferral of authority over WWI archaeological remains to centralised heritage authorities.
Over time, WWI archaeology increasingly became a concern of Flanders Heritage. The prime catalyst of this was the proposed extension of the A19 road through the frontlines at Pilckem Ridge, the location of key action during the Third Battle of Ypres in 1917. Starting in 2002, the agency conducted fieldwork there, ahead of the planned roadworks. Throughout this time, however, the Diggers continued to operate and their activities regularly reached the national press, for instance with the discovery and subsequent reburial of 25 German soldiers in late 2004 (Hendrickx 2004), and in a short documentary aired on national television on Armistice Day in 2005 (Dbj 2005). They also attracted regular foreign media attention, resulting in at least two documentaries, including the BBC's The Forgotten Battlefield in 2002 (Wemaere 2001;Saunders 2007, 19).
A new dispute arose in February 2006, when the Diggers were accused of removing large amounts of ordnance as well as human remains in advance of construction, under approval from the mayor but without permission from Flanders Heritage Agency (Pls 2006;NB 2006). In 2008, the case went before court, where two of the Diggers were accused of illegal excavations and selling finds. On 10 November 2008, both were convicted with a suspended penalty (Belga 2008a;. This marked the end of the Diggers' fieldwork activities, and the completion of the slow shift towards a fully professionalised WWI archaeology. From then on, the heritage agency's authority was fully established: the implications of the court case being that even WWI ammunition is to be considered archaeological heritage, and that every excavation requires a permit from the heritage agency. Since permits are, by law, only handed out to professional archaeologists, and mostly in direct relation to development work, this effectively made WWI archaeological fieldwork the nearexclusive remit of commercial units. I mean, it really became then a part of the archaeological heritage. The war heritage I mean. Before that it was more like amateurs and hobbyists and metal detectors, that were looking for finds. And also, there was a market for it, for things like that. But in 2002 it really became the archaeological, I mean archaeological awareness became really intensive . . . . . . from there on. And also all work for war heritage needed to be licensed. So that's a problem. That has been a problem with the Diggers, they weren't licensed. (FL2) Several newspaper interviews imply that this outcome was very much intended, referring to the court case as 'an example case' fuelled by jealousy and frustration (Pli 2008;Maes 2008).

Negotiating power in heritage
While interest in WWI, and especially the conflict heritage sites of Flanders and France, had waxed and waned in the years since the war, interest re-focused again in the run up to 2014. 'Official' attention on, and interpretation of, the region's WWI heritage had already begun before the centenary, but it increased in this time, with revamped museums, interpretation panels and centres (Shelby 2017). In addition to increased interpretation efforts for public consumption, research interests from professional archaeologists also increased, with the realisation that the former Western Front is 'one of the largest archaeological sites in the world' (Saey et al. 2013, 39).
The complexity of hobbyist engagements with WWI heritage is therefore refracted by the relations between the various stakeholders involved. These relations can be conceptualised as a competition over three domains of power: stewardship over heritage, control of the ethical norms associated with it, and the authority to present oneself as an expert. We take these concepts as points of departure for discussion of our findings.

Stewardship
The engagement of the Diggers with WWI heritage was entangled with local interests at various levels. Officials might not have regarded the archaeological remains from WWI as worthy of full protection and professional care until the early 2000s, but in the frontline region of Western Flanders, WWI heritage has economic importance. Tourism formed a major income source, even before the centennial. Connected to this, the Diggers' finds fed into local museums and numerous WWI sites became commodified for tourists. Furthermore, the presence of unexploded ordnance forms an obstacle for construction in the region, and therefore the provision of safe clearance that the Diggers could offer, was crucial for development.
Not surprisingly, local authorities and regional museums proved to be staunch public supporters of the Diggers and their activities, even during and after the 2008 legal proceedings (CMW 2008a;Pli 2008). The director of In Flanders Fields Museum deplored the impact of the court case over a year later, in an interview on the occasion of the first commercial ordnance clearings, stating that due to time delay and costs many developers were now tempted to ignore WWI finds, including human remains (Peeters 2009).
While these elements induced resistance and resentment to centralisation and professionalisation, larger-scale political factors drove those processes forward. WWI takes a central role in Flemish emancipation history (Van Everbroeck 2014). As such it is of particular interest to politicians seeking to promote a Flemish identity. This partly explains the many initiatives in the run-up to the centenary, including proposals to include the cemeteries and monuments on the UNESCO World Heritage list in 2001 and 2006 (Noppe 2013, 36). Thus, as the heritage sector in general has seen an increased emphasis on Flemish identity (Plets 2016, 198), the centralisation and professionalisation of WWI archaeology in particular was closely bound to a rising, politically supported, interest in WWI heritage (Noppe 2013, 46-47).
In addition, the Diggers' emotional investment in their activities, and the degree to which they personally identified as the first stewards taking up responsibility for this heritage should not be underestimated, and persists even to this day. In fact, our interviews reflected the relatively recent surge in professional and academic interest in the WWI archaeology, with one active hobbyist, who has in more recent years collaborated with professional historians and archaeologists, commenting: Nobody had an interest in what I was doing 30 years ago, and nowadays there's an official interest in it. So that's . . . That's, let's say, a kind of an achievement. Yeah, so I'm happy with that. (FL6) A sympathy for this attachment and a willingness to rebuild bridges (but no doubt also an attempt to recognise and incorporate amateur expertise) can probably be read in the establishment of the Association for World War Archaeology (http://www.a-w-a.be, active 2004-c. 2007). This initiative of government archaeologists who were closely involved in the earliest professional WWI fieldwork, purported to wish 'to direct the many, diverse initiatives undertaken by museums, amateur excavators, and historians by coordinating the expertise and different specialities of the various participants' (de Meyer and Pype 2004, 45). Stichelbaut et al. (2018, 19) confirm that projects such as the Diggers' Yorkshire Trench and Dugout excavations in Boezinge, as well as projects led by the Association for Battlefield Archaeology in Flanders (later known as the Association for World War Archaeology) and later the Association for Battlefield Archaeology and Conservation, 'all helped make public authorities realise that the material remains of the war were valuable'.

Control
However, one area of conflict and tension in relation to sites connected to war exists in how practice should be controlled in relation to ethically sensitive discoveries. Any investigationprofessional or otherwise -of WWI archaeology in Flanders is likely to demand ethical and safety considerations, namely through discovering human remains and unexploded ordnance (Saey et al. 2013, 40). This has not deterred amateur hobbyists, however, and the Diggers' investigations of WWI sites brought at first some recognition of their expertise -especially at the time that professional archaeologists had little to no interest in the period -but later also criticism for handling human remains and hazardous materials, as noted above.
The status of unexploded ordnance in particular, as part of the archaeological record and therefore the prerogative of licenced professional archaeologists, or, in contrast, as a dangerous and inhibiting factor in the local economy, has been a very concrete point of contention (Figure 2). Furthermore, the development of a centralised and professionalised WWI archaeology coincided with a discussion in Flanders about stricter regulation of non-professional metal detecting (Deckers 2019). Overall, the relationship between detectorists and the archaeological profession at this time was one of mistrust. In early 2003, parliamentary questions were asked about increasing antagonism from archaeologists towards detectorists (Deckers 2019, 105). In response to this, the minister struck a conciliatory tone, but emphasised that a permit is required for every form of archaeological excavation; in practice this rendered legal hobby detecting impossible. A 20-min television debate between a detectorist and the then-head of the Heritage Agency was broadcast in February 2003 (Vlaamse Televisiemaatschappij 2003). The encounter revealed the frustration of detectorists at the reduction of legal possibilities to practice their hobby. WWI archaeology was not mentioned in the parliamentary or television debates. In the press, however, Flanders Heritage Agency officials explicitly mentioned WWI battlefields (Jacobs 2003), asserting their authority over these sites and problematising metal detectors as a tool.
As González-Ruibal (2018) has noted: When archaeologists started addressing the sociopolitical context in which their research was carried out, in the context of the postprocessual paradigm, they were forced to take living people seriously and expand the scope of archaeological ethics, from mere objects to human beings.
This has to some extent led to a broader understanding of what ethics and ethical practice mean, although as others have noted much archaeological work still privileges the saving of archaeological data over other ethical considerations (e.g. Thomas 2020, 1078). At the same time, safety concerns around hazardous material such as unexploded ordnance are naturally important, although they can ultimately also play into perceptions of not only control over ethical and applied practice, but also over authority.

Authority
A final battleground was that for recognition as expert. In an international context, twentiethcentury conflict archaeology was experiencing a transition from hobbyist, leisure-time research to being regarded as an established scientific (academic) field of enquiry. From the late 1990s and early 2000s more and more research projects began emerging that investigated WWI, and the Western Front in particular (e.g. Desfossés, Jacques, and Prilaux 2000;Saunders 2002;also Novotny 2009). Running parallel to the professionalisation and bureaucratisation of field archaeology, it is likely that this discourse, not least as it included international researchers carrying out fieldwork in Flanders itself, had an influence on the way in which WWI heritage came to be viewed as the remit of trained, professional archaeologists. However, the claim of expert authority by the heritage agency was not easy to establish. Over the years, the Diggers developed a position as experts lauded for their voluntary engagement and respectful stewardship of WWI remains. After the first controversy related to the British documentary, several authoritative institutions supported the Diggers. Prominent Diggers members regularly featured in regional and national press as experts on WWI archaeology. In one national newspaper article from 2001, a BBC production assistant was quoted as saying '[The Diggers] are specialists, not bodysnatchers' (Bleys 2001). This, combined with the Heritage Agency's lack of experience prior to the A19 fieldwork, certainly contributed to the latter's difficulties in establishing their authority.
The terminology used to portray the Diggers' activities in the press further highlights the way their case was entangled with the wider debate about non-professional detecting. For instance, they were derogatorily called 'part-timers with metal detectors' by the director of the documentary 'Battlefield Scavengers' in 2000 (Naesen 2000). In an interview from the same period, an unrelated Flemish detectorist pointed to the Diggers controversy as having a negative effect on the hobby's reputation (Matthysen 2000). Perhaps this sentiment genuinely reflects a concern for the public image of non-professional detecting, but, since the activity had been illegal for many years, more directly it speaks of a growing fear of government restriction. Meanwhile the Diggers preferred not to present themselves as detectorists, but rather as knowledgeable amateur archaeologists. Especially during the 2000 controversy, they took care to distance themselves from allegedly less scrupulous 'colleagues' (Naesen 2000;Bwp 2000;P.S.P 2000;Van Puymbroeck 2000;De Stoop 2000). It was only in 2008 that one of the leading members mentioned using metal detectors during an interview (Goemaere 2008). Later, in an extensive online article published by the Flemish national broadcaster VRT, the metal detector features as a crucial tool throughout the history of the Diggers (Torfs 2014).
Today still, there is some local awareness of the expertise of non-professionals as compared to archaeologists (see also Verdegem et al. 2018, 75 for acknowledgement of the Diggers' impact), as demonstrated in the following exchange with a professional archaeologist regarding the knowledge of another hobbyist: Thomas: That's kind of nice, in a way, isn't it, because it's kind of recognizing a non-professional expertise. FL8: If the archaeologists . . . . . . go and find something . . . . . . Well, they call the museum and the museum calls that guy. So he's the one with the most knowledge about it. If you find a button, he will tell you who it was, which month and stuff like that. He will tell you if it's Canadian or British . . . It's a kind of expertise that our guys don't have. Why not use it if he's there and he's not, he's not doing anything wrong.
Another former non-professional who still maintained a collection of material from WWI but no longer was active, noted concerning one member of the Diggers in relation to changing professional perceptions of his expertise and skill sets: That's his frustration. That he found and knew more about WWI, than a professional archaeologist who was the boss, and they looked down on him. He didn't study . . . . . . He wasn't bad, but they looked down on . . . . . . He could never live with that. His relationship with a professional archaeologist, is, probably, was not good and probably still is not good either. This example highlights the tension, common to the interface between professional and amateur 'expertise', and the difficulties that often arise in negotiating these different roles and knowledge bases. The Diggers have been responsible for uncovering a vast amount of WWI material. Many museums feature artefacts from, and highly visible acknowledgements of, the Diggers. In the case of the In Flanders Fields Museum in Ieper this even includes a video of them in action. One of the professional archaeologists noted problematic issues with this apparent relationship, especially with regard to the legality of De Diggers' activities: I don't know many of those people except for the Diggers because they're more or less associated to the In Flanders Fields Museum . . . The museum had never the guts to say that they were not allowed to do it. (FL8) The Diggers' involvement with WWI remains dated to before professional archaeological interest. One interviewee emphasised the Diggers' connection with non-professional interest in WWI, as well as the exclusionary consequences of professional recognition of the significance of this heritage for non-professionals: The Diggers were . . . As I told you, the professional archaeologists were not interested at that time. I'm talking of the end of the last millennium. They were not interested, because they had other things to do. Middle Ages and so on . . . . . . That [WWI heritage] was for people who love working in the mud and finding rusty stuff like this and so on. Until their attitude changed understandably of course, it had to. And now they have taken over. (FL1)

Summary: Professionalisation and its implications
While the side-lining of amateur archaeology has been discussed as an outcome of professionalisation developments elsewhere, including but not only for conflict archaeology in particular (Novotny 2009;Willems 2014, 152), the case of WWI archaeology in Flanders is particularly interesting because the transitional phase -featuring both top-down problematisation and local resistance -was sufficiently high-profile to be well-documented in the press and well-remembered by those involved. These changes in archaeological stewardship, control and authority are typically presented as a matter of linear, serene institutionalisation (Saunders' [2007, 18-19, 153-161] discussion of the development of WWI archaeology in Flanders) and/or the gradual professionalisation of a group of amateur or antiquarian practitioners (Perry 2014, 6150). As Perry notes however, this may be an overly romanticised view, obscuring conflicts between competing factions, and muddying the complex and constantly-changing nature of archaeology as a discipline. Furthermore, politics of power as expressed through professional authority are well known within critical heritage discourse (e.g. Smith 2006). In cases such as this where there is not only attachment to the period itself, but also changes in attitudes towards particular actors -in this case the amateur Diggers -that add emotive and personal angles to the development of professional archaeology and its impact, bringing with it implications for wider public engagement with WWI heritage in Flanders.

Public participation after professionalisation
Professional archaeologists interviewed suggested that although the Diggers may have curtailed their activities as a result of the 2008 court case, it had not stopped hobbyist metal detecting and other non-professional searching from taking place: 'They have three of the Diggers, they stopped because of their legal problems, but for each Digger, there's a couple of other guys' (FL7). The advent of professionalised interest in WWI has nonetheless had an impact on the activity and also visibility of non-professional hobbyists: ' . . . now there is no amateur archaeologists anymore. That is . . . it's something that's underground now' (FL7). 1 From a touristic perspective, many visitors to Ieper come particularly from the countries that participated in the WWI battles in the area, especially Britain and British Commonwealth countries, in what might be compared to or described as a secular 'pilgrimage' to remember the war dead, with perhaps until recently less interest from the local residents. Over time, other drivers have joined the motivations for visiting sites such as educational visits, nature tourism and general leisure, attracting visitors from elsewhere including Belgium (Winter 2011). At the same time, the WWI legacy in Flanders is nonetheless dissonant. One interviewee suggested that the perception of the heritage as more strongly connected with other countries had contributed to an ambivalent feeling within Belgium: We as Belgian people don't have any or the same connection. We do not have the same connection with this heritage as people from the UK have with these cemeteries or monuments. And it's also interesting to see that the heritage is something that's on a foreign land, so . . . So it's not like the church and your own municipality. It's abroad . . . So distance between these relics, this heritage and the people from where they come, it's sometimes quite big. (FL7) However, this assumption of less personal connection is not necessarily a universally held viewpoint. Pollard and Banks (2007, iv) also questioned the extent to which it was fair to suggest that only British and other Commonwealth archaeologists exhibited an interest in this heritage, noting an upsurge in interest from both French and Belgian archaeologists. Furthermore, two interviewees (FL1 and FL5a) noted that their grandfathers -in the Belgian military -did serve in WWI. There are also other traditions and understandings that can connect people to cultural heritage, such as the phenomenological fascination with historic landscapes and objects: Oh my god, this is so interesting. Especially if you're a little boy, then a shell and a gun and . . . It's always amazing to find them. Then I put it on my bike at the back, and I came over. "Oh what's that?" "It's a shell from the First World War." "Go back to the farmer!" . . . . . ..And especially when the Diggers came in that period, I think that was in 1994, they started in the industrial zone of Boezinge . . . Then they found a body, and I never saw a skeleton in my whole life, and then you see bodies, and it's something that takes your attention. (FL4) On the back of development in the region, WWI archaeology has now firmly established itself as a subfield within Flemish archaeology, both on an international level (e.g. Saey et al. 2013;van Hollebeeke, Stichelbaut, and Bourgeois 2014;Stichelbaut et al. 2018), and regionally (e.g. the annual 'Conflict in Contact' conference, focused on battlefield archaeology in general but with many WWI contributions and organised by several leading Flemish WWI archaeologists). Public engagement has been largely restricted to one-directional communication (e.g. site tours, museum visits, popularising articles in general and specialised press), reflecting broader concerns with the top-down, controlled nature of public archaeology (e.g. Apaydin 2016, 838-839). Recent, more participatory developmentssuch as the crowd-sourced 'Hill 80ʹ excavation project in 2018 (Stichelbaut et al. 2020, 172-177) or the establishment of a permit scheme for detector hobbyists (Deckers 2019) herald the return of some agency to the wider public (also see Wijnen, Schute, and Kok 2016 for discussion of the potential of twentieth-century conflict archaeology for community engagement in the Netherlands). This echoes earlier participatory projects elsewhere that have harnessed non-professional knowledge and enthusiasm to benefit the study of twentieth-century conflict heritage positively, such as the Defence of Britain project that was coordinated by the Council for British Archaeology and the Fortress Study Group in 1995 (Schofield 1999, 10). However, the heavily regulated frame within which this takes place, makes it equally clear that in this network of stakeholders, the potential of conflict over stewardship/ownership, ethics, expertise and other aspects of heritage engagements is as present as ever.

Conclusion
The WWI heritage of the Western Front, particularly in Flanders, has been iconic for remembrance since before the war even ended. Over time, it has found itself viewed as a tourist attraction, a site for pedagogical experiences, and increasingly a subject for scientific research as a complex archaeological feature. Also present, but previously often marginalised in discussions on the site or dismissed as 'looters', are the hobbyists who have spent time making their own investigations on the area -with differing degrees of archaeological rigour. At the same time, politics over the ownership of WWI heritage continue to attract debate, with the additional lens recently noted that within the context of Belgium, Flemish identity -especially connected to cultural heritage -has increasingly come to the fore, even ahead of a national Belgian heritage.
It is clear from here but also from other instances in the globe, that archaeological professionalisation is far from a linear development. We see in this case and elsewhere evidence of power struggles between the professionals and other groups (especially amateur hobbyists) over archaeological stewardship, control of ethical practice and expert authority. Public participation should be seen as a long-term negotiation of interests and control, often resulting in friction between emotional attachment, local interests and administrative procedures. In the present time, while public participation is possible, the balance of power (and recognition of expert authority) sits firmly with the archaeological professionals.