Franz Steinkühler was born in Würzburg. His father worked as an electrician at the time of his birth, but later switched to a career with the police service. During the war, which broke out in September 1939, much of Würzburg, which was still in large part a timber built city, was destroyed by Anglo-American bombing and a particularly destructive resulting fire storm. Survivors, including the Steinkühler family, were evacuated to Lower Bavaria. They subsequently relocated again, this time to Göppingen (Stuttgart) in Württemberg.