By April 15, 1941, the Royal Hellenic Air Force was virtually eliminated by the numerically and technically superior German Luftwaffe.

[7] On May 14, 1944, the Squadron was transferred to southern Italy, where operations included bombing of enemy positions in Yugoslavia and Albania, as part of the Allied Balkan Air Force.

During this period it executed a total of 1,400 operations that included bombing train stations, bridges, ammunition and fuel depots.

[8] On November 14, while the Axis troops were retreating from Greece, the aircraft of the Squadron landed in Hassani Airfield (later the Hellenikon Air Base and Ellinikon International Airport), near Athens.

Alongside the Spitfire fighters of the two other Greek Squadrons, 335th and 336th, which had also arrived in Greece, the 13th was engaged in bombing missions against the remaining German garrisons in the Aegean islands and Crete (April–May 1945).