The Soviet Union’s diminutive Polikarpov I-16 played an important part in the Spanish Civil War. Malcolm V Lowe outlines its frontline use during the conflict

The Spanish Civil War, fought between 1936-39, was very much an armed rehearsal for World War Two. Several countries found the conflict useful for testing military equipment, on the ground and in the air. The fascist powers of Germany and Italy donated masses of military aid to the rebel forces of General Franco, while the Soviet Union supplied a smaller but nonetheless important amount of materiel to the embattled Spanish government. Among the aircraft types delivered to the Republicans was a significant number of Polikarpov I-16 fighters, which proved to be a match on many occasions for their German and Italian adversaries.