Mathias, the black servant, was actually a South African corporal, Mathew Letuku, who had been captured by the Germans and served as a driver. Marseille adopted him as his personal servant and driver (much like a British officer's "batman"), and they became fast friends. Marseille made his fellow officers promise him that Mathias was to remain with the unit if something happened to him. They kept that promise, saving him from an uncertain fate in some PoW camp, and when the war neared its end, they infiltrated Mathias in a temporary camp where he could be liberated without no one being the wiser. Years later, he was invited to one of the veterans' reunions, and was greeted with genuine friendship.
Jochen Marseille's girlfriend "Brigitte" is based on Marseille's real life fiancee Hanne-Lies Küpper, who was also working as a teacher in Berlin. She also came with him to Rome where they spent a vacation. She died in 1987 in the age of 81.
After the premiere of the movie in August 1957 the mother of the real Hans-Joachim Marseille, Charlotte Reuter-Marseille, thanked Joachim Hansen for his performance in portraying her son.
The event in which Jochen Marseille landed with his airplane on the Autobahn actually did happened in 1939. But unlike in the movie he didn't want to check on the location but had to go to the toilet.