Immediately following the end of the First World War, the air force of the newly-formed Southern Slav State, the Kingdom of Serbs, Croats and Slovenes, was forced to rely mainly on war-time Serbian Air Service aircraft and material left after the withdrawal of the French Arm e de l'Air from the Balkans in 1919/1920. This equipment was supported by the addition of French war surplus stocks which started arriving in 1921.

In 1929 the monarchy changed its name to the Kingdom of Yugoslavia. Then, from 1930, the official name of the air service branch its military was changed to what is commonly known in the West as the Royal Yugoslav Air Force (RYAF). The obsolete First World War aircraft were replaced from 1925 onwards by stop-gap solutions purchased mainly from France, some from the Czechoslovakian Republic as well as from the first domestic factories.

From 1936, the RYAF again began to reorganize and modernize, with the purchase of the most modern aircraft available at that time. These aircraft were imported from the UK, Germany and Italy, some being built under licence in domestic factories. During this period the Kingdom of Yugoslavia succeeded, as much as conditions allowed, to equip its air force with the most advanced fighter and bomber types of the period.

For the Kingdom of Yugoslavia, the Second World War started on 6 April 1941. The military coup d'etat of 27 March 1941 and anti-German demonstrations in Belgrade clearly aligned the kingdom with the Allies. That same day, Hitler ordered the implementation of Unternehmen 25 (Operation 25) - the attack against Kingdom of Yugoslavia. Hitler had also secured Mussolini's support for this campaign, while Hungary, Romania and Bulgaria gave active or passive backing in exchange for territorial claims in Yugoslavia.

Despite all the odds, the airmen of the RYAF fought gallantly in the defence of their homeland, with fighters taking on the German and Italian bombers and their escort fighters - including the Axis types in service with the RYAF.

Eventually, due to the deteriorating situation on the front and the ever-increasing risk of the king and his government being captured, the decision was taken to evacuate by air to Greece. In the summer of the 1941 some 220 Yugoslav aviators gathered in Egypt and continued the fight against Axis, this time in the colours of the RAF. This is the full story of their service and combats in the early months of that year.