On my neverending internet travels, I found out about an alternative Batman story called “The Berlin Batman”, set in Berlin, Germany during the Second World War. It tells the story of Baruch Wane, a wealthy Jewish painter who conceals his faith and identity in the light and the dark for he is the mysterious Batman, a masked vigilante fighting the Nazis.
“The Berlin Batman” came as part of the DC Comics imprint, Elseworlds, and was published in The Batman Chronicles #11 (you can also read it for free on Read Comic Online)
More on alternative Batmen: What if Batman was Black?