In the beginning of 30s it was appeared in the world an idea of high-speed bomber that could outstrip contemporary fighters. One of the objectifications of this conception became the twin-engine bomber He 111 designed by a German Heinkel Flugzeugwerke AG company.
Since the November of 1939 it were produced He 111H-3 planes with liquid-cooled Jumo 211D-1 engines of increased power and more powerful armament.
In early 1940 it were produced 504 He 111H-3 bombers. They took part in all 1940-1941 Luftwaffe operations.