Danish football fan alliances have become a growing concern for police after a new book on the country’s extremist supporter scene argued that rivalries once contained around stadiums now increasingly spill across borders, drawing in foreign ultras and complicating security planning.
The claim comes from Bag tribunen – politichefens møde med fodboldens kampplads, published on 17 March by Politikens Forlag, written by journalist Maya Westander with former senior police official Mogens Lauridsen. Drawing on past cases, the book describes how parts of Denmark’s fan scene developed ties not only with foreign supporter groups but also with environments shaped by local biker subcultures and their codes of loyalty, hierarchy and confrontation.
Dortmund showed how Danish rivalries had gone international
One of the clearest examples in the book is the unrest around FC Copenhagen’s Champions League match in Dortmund on 5 September 2022. According to the account reproduced by TV 2 Sport, Danish police had prior intelligence suggesting that hardcore Brøndby supporters would travel to Germany, where some had long-standing ties with Borussia Dortmund fan groups.
The book argues that the trip was not mainly about supporting the German side. Instead, it became tied to hostility toward FC Copenhagen, whose supporters were in the city for the European fixture. In central Dortmund, groups of ultras linked to Dortmund and Brøndby allegedly attacked FC Copenhagen fans before the match, while pyrotechnic incidents later added to the disorder inside Signal Iduna Park.
For Danish police, the episode illustrated a broader shift. Domestic rivalries were no longer limited to Copenhagen or the Superliga calendar. They could reappear abroad, in cities where local allies, unfamiliar supporter networks and different legal frameworks made the security picture harder to control.
Why police risk assessments became more complex
Lauridsen’s account suggests that the policing task changed fundamentally once Danish fan groups built stable relations with foreign counterparts. The issue was not only the risk posed by Danish supporters themselves, but also the presence of travelling allies whose numbers, internal structures and intentions were often less familiar to local police.
That meant risk assessments increasingly depended on cross-border intelligence-sharing and closer coordination with foreign authorities. The book also argues that Danish football’s governing bodies had limited room to shape some of the most sensitive international fixtures, leaving police to rely on preventive measures, surveillance and legal tools rather than broader competition-level restrictions.
Longstanding friendships link Danish clubs to foreign groups
The book places the Dortmund events in a longer history of supporter alliances. It describes how Brøndby built connections with Borussia Dortmund and earlier with Malmö FF, while FC Copenhagen developed strong links with Hamburger SV and, in earlier years, with Helsingborgs IF.
Such ties were often visible first in choreographies, shared banners and mutual visits. Over time, according to the book, some of them also extended into more confrontational parts of supporter culture, including organised fights away from stadiums. That evolution matters because it blurs the line between fan culture, hooligan networks and more tightly knit subcultures shaped by loyalty and territorial identity.
The return leg in Copenhagen prompted stricter controls
The events in Germany had consequences ahead of the return match in Copenhagen in November 2022. Danish police publicly warned that groups of Danish and German supporters could come to the city with the aim of causing disorder, and they sought stronger preventive measures before the game.
UEFA did not approve a request to stage the match without away fans, so authorities turned to other tools. These included a stricter penalty zone around Parken and tighter controls on ticket sales. Borussia Dortmund also moved to personalised away tickets, a step that later became a point of protest among the club’s ultras.
Before the match, police intercepted a large group of Brøndby and Dortmund supporters travelling toward Copenhagen and reported finding mouthguards and weapons discarded in the area. On the day of the game itself, however, the area around the stadium remained calm and the fixture was played without major disorder.
A broader debate about the darker side of Danish fan culture
The wider argument of Bag tribunen is that the most violent edges of Danish football support cannot be understood only through matchday incidents. The book presents them as part of a more durable ecosystem of identity, prestige and organised confrontation, one that has evolved over decades and occasionally overlapped with biker-style subcultures.
That does not describe Danish football fandom as a whole. Most supporters are not part of violent groups, and the book focuses specifically on the extremist fringe. But its account adds weight to a debate already familiar in Denmark: whether the current balance between dialogue, intelligence work and sanctions is enough when fan rivalries are reinforced by cross-border alliances.
What the book adds to the Danish debate
The main value of the book is not that it reveals a single new scandal, but that it connects separate incidents into a wider pattern. In that pattern, Danish football fan alliances are no longer a side story about friendship between terraces. They are part of the security challenge itself.
For Denmark, the broader implication is that football-related violence can no longer be assessed only as a domestic policing issue. When supporter conflicts travel with clubs, European matches can also become meeting points for old rivalries, foreign allies and pre-arranged confrontations far from the stadium. That gives the issue a wider Nordic and European relevance, especially as police forces increasingly depend on international cooperation to prevent violence tied to sport.
