Since football is tribal our allegiance for the 1999 European Cup final between Manchester United and Bayern Munich was clear. I was an Arsenal fan and my Israeli friend supported Liverpool, so we were both cheering the Bavarians.
Only my friend's daughter was puzzled: "Daddy, why do we want the Germans to win?" He thought for a moment: "For Jewish reasons!"
It was a good joke. For decades Germany's biggest club was unfairly seen through the gauze of its home city's history of beer halls and Brownshirts. And yet, as Bayern prepare to face another English team, Chelsea, in this season's Champions League final - and with Jewish Spurs fans rooting for a German victory, which will mean Champions League qualification for their team - the joke turns out to be true.
In pre-Nazi Germany Bayern was a club of Jewish visionaries. It was sponsored by Jewish businesses and became a beacon of tolerance and cosmopolitanism. The Nazis suppressed it, and a mixture of post-war guilt and simple ignorance kept the story hidden.
Now it has been brought to light by Dietrich Schulze-Marmeling, one of Germany's leading football historians, and is slowly being re-embraced by the club.
The key figure in the story is Kurt Landauer, a stout Bavarian from a wealthy Jewish family who was club president from 1919 onwards and made little Bayern into one of Germany's most dynamic football institutions. Landauer shared the vision of his friend and mentor Walther Bensemann, an even more important Jewish German football pioneer, that the game could create friendships between nations. Landauer rejected the notion of Kampfgeist ("spirit of struggle"). Rather, he saw football as a game of creativity, artistry and joy.
Bayern's 1-7 defeat at the hands of the Budapest club MTK in 1919 changed his life. MTK was another "Jewish club", and played stylish, intelligent, quick-passing football. Landauer was so impressed by the Hungarians that he spent the next decade recruiting as many of them as possible to Bayern, and all of them happened to be Jewish.
Rarely has so much coaching talent passed through the doors of one club - talent like Izidor "Dori" Kürschner who would later flee to Rio and help lay the foundations of Brazil's beautiful game, and Kálmán Konrád, who coached Bayern for a season and, in 1999, was picked by World Soccer magazine as one of the 100 greatest players of all time.
By the early 1930s, Richard Dombi, a Viennese Jew, was one of the most coveted managers in Europe. He led Bayern to its first championship in 1932.
In short, Landauer had turned Bayern into a bastion of enlightened values and good football. The club had the best youth training system in Germany and was pushing for professionalism. And it was all doomed. As Schulze-Marmeling says: "Bayern Munich was like a little island in a sea of antisemitism".
In the years after the Nazi takeover of Germany in 1933, football was "Aryanised". Yet Bayern continued to hold out, after a fashion. The club's Jewish members, players and administrators were forced to leave. Many were later murdered. Albert Otto Beer and Berthold Koppel, two Jewish textile merchants and club members, were deported and killed. Another, Siegfried Weisenbeck, committed suicide. During the Nazi period, local rival club 1860 Munich collaborated with the new authorities, but Bayern selected non-Nazi presidents while Landauer secretly ran things behind the scenes. This ended when he was arrested on Kristallnacht in 1938 and briefly held in Dachau.
Landauer's three brothers and a sister were murdered in the Holocaust but he escaped to Switzerland and returned as club president in 1947, dying in 1961.
"We have to be very careful about calling Bayern a Jewish club," says Schulze-Marmeling, who has been researching the subject for nearly 20 years and whose Bayern Munich and its Jews was voted Germany's best football book last year. "Bayern was an open-minded club with no antisemitism, so you could feel at home there. But I found only one Jewish player, a goalkeeper called Bernstein who was playing in 1926."
For decades, though, Germany's footballing Jews were invisible. Standard histories dismissed even giants like Bensemann in a single line and ignored the persecution or murder of Jewish officials and players. As recently as 2001 a journalist asking about Bayern's Jewish history was told by a club press officer: "We are not interested in these things".
Yet now Bayern supporters drape giant banners of Landauer across the stadium and club officials routinely call him "the father of modern Bayern Munich". In 2009 the club marked the 125th anniversary of his birth with a memorial event at Dachau.
"These people were written out of history because a lot of football officials collaborated with the Nazis and they didn't care about their former comrades," says Schulze-Marmeling. "It is interesting that for so many decades no one questioned this. But things have changed a lot." He gives Karl Heinz Rummenigge, a star of the '70s and '80s who is now club chairman, much of the credit for reconnecting Bayern with its Jewish past. "You get the impression it has become a personal thing for him," he says.