During the Spanish Civil War in 1936, the Soviet Union observed the highly effective German Flak 88 in use by Republican Forces and developed the 85mm M1939 (52-k) Anti-Aircraft gun based on the German Flak.

Like the German Flak, it was discovered the M1939 was also effective in anti-tank roles. With the cannon modified, it was used in the T34/85 Tank, the SU-85 self propelled anti-tank gun, and the D-44 85mm Divisional Gun.

While the T34/85 and SU-85 are no longer in use, the D-44 has been observed in current use by both Russia and Ukraine.  They are also present in the Middle East, Africa, North Korea and most former Soviet allied countries.