Of course, as we all know, Germany was not allowed an air force under terms of Versailles. That was openly broken in 1935, and more covertly earlier.
One of the interesting matters was the choice of single seat fighter. As most of you know, the Messerschmitt Bf109 was the choice. In second place was the Heinkel He 112.
Though they saw service in the Spanish Civil War in the
Legión Cóndor, and were used in the Romanian invasion of USSR, they had a limited production.
An excellent article can be found at
Heinkel He 112 and is well worth reading and discussing. Also see
FLUG REVUE January 2000: Heinkel He 112 story.