1904 - Janos Prohaska is born in Poland.
1914 - 10-year-old Janos learns to shoot during WWI when his home is destroyed in a bombing.
1918 - 14-year-old Janos's family resettles after WWI.
1921 - 17-year-old Janos joins the newly formed Polish Air Service.
1931 - 27-year-old Janos ends his service with the Polish Air Service & becomes a soldier of fortune. He enlists the aid of Stanislaus Drozdowski, who is just out of university.
1936 - 32-year-old Janos fights in the Spanish civil war for the communists.
1939 - 35-year-old Janos's brother and sister are killed when Germany bombs Poland. He travels to Britain to join their Air Service, but is slowed because he is not a British subject. He and several other European pilots form the Blackhawks.
1941 - WWII begins.
1947 - 43-year-old Janos & the Blackhawks help the Creature Commandos kill Hitler's brain. Janos begins working with the postwar Justice Society.
1951 - 47-year-old Janos is trapped in Ragnarok with the rest of the Justice Society, and dies escaping.
After the decline in superhero popularity that followed the end of World War 2, there were only four comic characters that saw continued publication that lasted right up into the resurgence of superhero comics in the fifties: Superman, Batman, Wonder Woman.... and Blackhawk. It's not a fact we have a ready explanation for... the Blackhawks were an absolutely awesome little nugget of dramatic wartime heroism, but the whole concept really falls apart the second you start to apply any sort of whimsical comic book logic to it. This is a story clearly meant to exist only during the height of the war.
Following that logic, we've deliberately constructed the timeline of our Blackhawk Squadron around the history of aviation within various European countries. The notion of airplanes as a weapon of war took off during WWI (just ask Snoopy), but different countries obviously adapted the technology into the infrastructure of their military at their own pace. Because the Blackhawks were always a collection of pilots from across occupied Europe, it made sense to do a little research and figure out exactly what that would mean for each character.
As for Janos himself, we made sure to include his time as a Soldier of Fortune and his service during the Spanish Civil War, but because he's the only member of the squadron to actually take the name 'Blackhawk' we gave him a more traditional superhero backstory, and also expanded his career to have him become a defacto member of the postwar Justice Society.