Hamburg’s FC St Pauli occupies a distinctive position in world football. A bastion of leftwing activism and DIY arts, its supporters, particularly the legendary “Ultras”, are one of the western world’s most politically and culturally engaged fanbases, and the club is particularly beloved of punk and underground music fans. “St Pauli is unlike any other club,” says Tim McIlrath, frontman of American melodic hardcore band, Rise Against. “We went to their stadium, and to see ‘No Football for Fascists’ painted across the stand, to see them encouraging more girls playing football – it’s fascinating. I was looking for a club that transcends sport – St Pauli is a model of that.”

It’s late May, and FCSP are hosting Antira Sankt Pauli 2018. Antira for short, it is an annual international anti-racist football tournament to which progressive, fan-led global teams are invited. As the 2018 World Cup begins, promising to be a carefully orchestrated showcase of Putin’s Russia, this inclusive, DIY contest is an interesting counterpoint to the Fifa pageant. “Everybody in Europe should be concerned about the new far-right movement,” club president Oke Göttlich tells me inside the club’s Millerntor-Stadion. “We are not a party, we only can make our values heard. But we all need to stand strong. If St Pauli can play a little role in that, we are as happy as if we won a football match.”

A mixed match at the Antira tournament, May 2018. Photograph: Peter Boehmer/the Guardian

From the outset, the atmosphere is jubilant, as enthusiastic participants waste little time in introducing themselves to one another, buying rounds and cheering each team (male, female and mixed) equally. I spend most of my time with East London’s Clapton Ultras, who praise the sense of community that they’ve found in this network of politicised sporting groups. “We’ll probably get beaten a lot though,” one player shrugs. “Because some of the other teams are actually … fit.”

True, this is hardly the most technically impressive football tournament I’ve watched, but it’s also the only one at which pints of lager are passed along the touchline between substitutes. The setting, though, is exceptional: a manicured Bundesliga 2 pitch in a 32,000-capacity stadium, adorned with progressive slogans (“no human is illegal”, “football has no gender”). There’s a decent showing from British sides: Republica Leeds win the women-only competition, and Bristol’s Easton Cowboys claim the mixed-gender title alongside Berlin’s TeBe Party Army. Yet these victories seem beside the point: at the closing ceremony, each team presents another with a gift, each of roughly equal value.

Away from the pitch, the Millerntor-Stadion and the surrounding area play host to a number of non-footballing events, including a workshop at which representatives of each team detail their concerns about the far-right in their homelands. DJs pump hardcore punk, ska, dub and electro through a soundsystem overlooking the pitch, and on Saturday evening, we’re treated to sets from Italian punks Bull Brigade, Connecticut rapper Ceschi Ramos, and Stuttgart ska band No Sports.

Rise Against’s Tim McIlrath at Germany’s Rock am Ring festival, June 2018. Photograph: Markus Heine/EPA

Each night, after the official Antira events have concluded, I’m whisked off by locals to various other DIY events around the area, further underlining St Pauli’s deep-seated musical connections. I find myself at two techno parties, the first in a cavernous community centre in Altona, and another in Flakturm IV, a former Nazi air defence bunker. A hulking mass of concrete and steel designed to withstand allied bombing, Flakturm IV dwarfs the Millerntor. Once inside, we’re nodded through a back door for a look from the roof of the building, thanks to the bouncers’ relationship with the Ultras leading our group. Apparently FCSP Ultras are often employed as security staff in Hamburg because “they’re intelligent, but know how to fight”.

To further add to the team’s punk credentials, their recent off-season American tour included a stop-off in Detroit for a Rise Against show. They’re far from the only band in thrall to St Pauli. Acts from Norwegian metal band Turbonegro and London indie group Art Brut to Icelandic post-rockers Sigur Rós and New Jersey rock outfit the Gaslight Anthem are vocally supportive. “They were one of the first clubs to not allow racists in, and they’ve been pretty left [wing], and punk rock,” Gaslight guitarist Alex Rosamilia has said. Punk and metal bars across Europe and North America are plastered with FCSP stickers and memorabilia; the team walk out to the strains of AC/DC every home game.

There’s a sense of urgency in many artists’s statements about FCSP. “To stand for ideals together with FCSP is a big honour for us,” says Dema, frontman of Italian ska-punks Talco. “Especially to spread antifascist and antiracist views in a society in which the important and real things are brought out of focus.” Rise Against’s McIlrath adds: “Sport can provide sanctuary to a lot of rightwing motivations and hooliganism – FCSP taking a proactive stand against that is exciting.” And as one middle-aged Ultra tells me, FCSP supporters’ musical interests go beyond punk and metal. In the 1980s and 90s, many Ultras eschewed “cheesy German punk” for dub and reggae. His sentiment still holds – many of the younger supporters have little to do with rock and are active in Hamburg’s DIY techno, house and Afrobeat scenes.

Ceschi performs at the Antira party at Knust, May 2018. Photograph: Peter Boehmer/the Guardian

It’s increasingly rare to see a subculture blossom to this extent, certainly in the middle of a major western European city. Yet it’s writ large across Hamburg, even away from its nucleus in St Pauli. One factor may be the German government’s fiscal attitude to culture: as Arts Council England’s year-on-year budget reduction since 2010 continues with a further cut of £156m by 2022, German culture minister Monika Grütters has proposed an increase to national arts funding of €302m (£256m) a year.

Affordable housing plays a part too – in 2015, Hamburg’s local authority became the first in the world to pass a law allowing the seizure of empty commercial properties in order to house migrants. Unlike London’s more covert equivalent, the city’s squat scene is not only well-known, but highly visible, particularly around such landmarks as the Rote Flora. This results in lower rents and far more public land, affording residents more time and space to engage with art, politics and charity. Combined with a port economy that relies heavily on unionised industry, and given a social institution around which to congregate – FC St Pauli – counterculture has thrived.

The St Pauli flag, pictured at a Bundesliga match between VfB Stuttgart and FC St Pauli in 2010. Photograph: Thomas Niedermueller/Bongarts/Getty Images

However, this is not an uncomplicated, wholly positive situation. I’m not alone in noticing a disconnect between the tournament’s messages and its demographic; the vast majority of people here are white, more often male than female, and although there may well have been a significant LGBT+ contingent in attendance, their presence was rarely explicit. And this subculture does not exist in a peaceful, progressive bubble. Clashes between FCSP fans and far-right hooligans are commonplace, and the Ultras are famously active in antifascist violence. Furthermore, the Millerntor sits, quite literally, between two problematic issues: the gentrification of St Pauli, which forces its resident subculture away, and the organised crime that’s bolstered by the red-light district around the Reeperbahn. There are real tensions here.

Nevertheless, a subculture on this scale, encompassing music, sport and politics, feels refreshing in 2018, particularly given the grassroots work that FCSP does for refugee and antifascist causes. Without this subculture, those good deeds may go undone; without comparable subcultures, who knows what else we’d lose? As Göttlich says, “If a musician is not working closely with his fans, the musician will disappear. A fan community is something to nurture. Our fans don’t always do everything right, but they are what make St Pauli special.”