Hamburg, Germany (CNN) -- On the docks of the German port city of Hamburg, the district of St. Pauli blinks with brightly-colored neon signs advertising countless sex cinemas and private dancers.



This, after all, is where you will find the Reeperbahn, one of Europe's most infamous red-light districts, an area with proud memories of when The Beatles played the raucous venues of the town over a two-and-a-half-year period before they became the most famous band in the world.

But now it is the skull and crossbones -- which fly from almost every shop front and street corner -- rather than sleaze that defines this working-class district of Germany's second city.

The notorious black and white standard isn't a sop to the city's seafaring past, but rather a homage to one of the area's most famous sons: FC St. Pauli, often described as the most left-wing team in the world, who will this season take its place among Europe's footballing elite in Germany's Bundesliga.

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"A lot of squatters from the well known squats down at the docks in the 1980s brought a skull and crossbones flag to the club, as a joke, but it spread," explained Sven Brux, a lifelong supporter and head of fan organization and security at St. Pauli.

"It's a symbol: we, the poor, are against the rich, rich [clubs] like [Bayern] Munich. Like pirates fighting for the poor against the rich. Now it's an official club symbol."

St. Pauli had traditionally lived in the shadow of the city's big club Hamburg SV. But during the 1980s, local squatters, anarchists, prostitutes, students and punks started filling the creaking terraces of the Millerntor Stadium, giving it a very different character.

While the rest of European soccer was mired in racism and violence, St Pauli took a more progressive path, launching anti-racism and anti-homophobia campaigns years before other clubs followed suit.

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"We were the first club saying this 20 years ago," recalled Brux. "We were the first club wearing T-shirts, saying that racist things were forbidden and at the time no-one in Germany cared about these things. Our fans were the first to say we don't want these things in football."

Ever since the side and its fans have actively campaigned on progressive issues. This year it organized a tournament for recently arrived refugees. In 2006 St. Pauli hosted a World Cup for unrecognized nations, giving the likes of Tibet the chance to raise their flag for independence. On one occasion they even arranged a friendly with Cuba to show solidarity with Fidel Castro.

But it is the organization's relationship with its fans which remains unique. Although German football is seen as more fan-friendly than most in Europe, thanks largely to popular policies like retaining standing areas in stadiums and the so-called "50+1" rule, which prevents football clubs being owned by any one powerful individual, St. Pauli can do little without consulting its fans first. Recently the club agreed, after pressure from fans, to never sell the naming rights to the stadium.

Unsurprisingly, the anti-commercial credo which has given the club such a cult following has left St. Pauli at something of a financial disadvantage when up against the likes of European giants Bayern Munich.

Previous stints in the Bundesliga have been brutally swift. Their last, in 2002, saw them finish a distant last after winning just four games. Relegation soon after to the German third division almost killed St. Pauli off for good until the arrival of Corny Littmann, a successful theatre impresario and the first openly gay president in German football who was charged with the task of trying to square principle with economic viability.

"The club financially was at the end; it was a question to go on or just to let it die. It was a really hard time, in 2003, all players left the team. The club didn't have any money at all," recalled Littmann. "It was always the main question: how to save the identity of the side and, on the other hand, know we are a professional football club?"

Littmann, who left the post in May, heavily marketed the St. Pauli, a club which, according to sports marketing agency UFA Sports, has over 11 million fans worldwide. Now the St. Pauli sells $8.6 million worth of merchandising a year and has redeveloped the stadium to include business seats, reforms that were unthinkable a few years ago but which arguably have saved the club from extinction. But Littmann knew there were limits to how far he could go.

"Every club in Germany has a main sponsor; Hamburg [SV] gave the naming rights to the stadium to a third big company in 10 years. How can you build an identity when you change the name of the stadium? We decided not to give the name of the stadium to a company, but it has cost us millions every year."

"And Hamburg buys players cheap and sells them high. How can you build up an identity with the team when you are just a football shop for Europe? Now we follow a philosophy where we want young German players -- this helps identification between fans and the club."

One person who has been outspoken about the club's anti-commercial principles is the team coach Holgar Stanislawski, who played 200 times for the club before dragging St. Pauli back to the Bundesliga from the third division.

"Some fans don't like it, merchandising [and other commercial considerations] and want us to play in the third league," he told CNN. "But if you want to play in the Bundesliga you must go this way, you must build a new stadium. We have €50 [$64] million for this season, everyone else has €80 {$102] million. But you must be St. Pauli too. And that's the difficult thing here."

Yet the old rebel spirit still remains on the terraces. Fan groups like Ultras St. Pauli, who insisted CNN deleted video footage of them collecting money outside the ground for fear that the police would use it to stop their "anti-fascist action," still clash with the club, and occasionally the authorities, on matters of principle. And the club's punk roots remain in FC St. Pauli's bar, the Jolly Roger, an unreconstructed punk venue.



But for most St. Pauli fans, this season has only two aims: to remain as true to its progressive principles as possible and to beat hated rivals Hamburg SV at the Millerntor next month.

"St. Pauli is a way of life. We are not a club that wants to make money, we just love soccer," explained Daniel, a fan watching St. Pauli beat Spanish side Racing Santander in the club's final home pre-season friendly. "Even if we go down to the second division again it doesn't matter. It doesn't matter."