After the Russian revolution of February 1917, the Estonian state obtained a degree of autonomy within Russia, which included the establishment of national armed forces. Thus many Estonians in the Russian Army returned home to take up arms for their homeland. The Estonian declaration of independence in early 1918 was not recognised by Germany, which invaded and occupied the country during 1918. The Estonian armed forces were disbanded.
Germany surrendered on 11 November 1918, and the Estonian provisional government immediately set about establishing a military aviation unit. The Aviation Company of the Engineer Battalion began to establish air bases near Tallinn for seaplanes and landplanes, but it wasn’t until January 1919 that the first operational aircraft was acquired – a captured Soviet Farman HF-30.
In the meantime, on 22 November 1918, the Soviet Red Army had attacked Estonia and soon occupied most of the country. The fledgling Estonian Army, with foreign assistance, managed to counter-attack in early January 1919 and went on to liberate the country by late February. It subsequently moved on to liberate Latvia. Aviation Company aircraft flew a limited number of missions in support of the army.
Following the February 1920 peace treaty with the Soviet Union, the Estonian Army was demobilised but the Aviation Company was retained. With the delivery of more aircraft it was reorganised as an Aviation Regiment (Lennuväe rügement), comprising a landplane squadron, seaplane squadron, flying school and workshops. More bases and seaplane stations were built.
Some Aviation Regiment pilots were involved in a pro-Soviet coup attempt on 1 December 1924, but this was crushed within hours. From 1925 the First World War era aircraft were gradually replaced by more modern types. During 1928 the Aviation Regiment came under the control of an Air Defence (Õhukaitse) organisation which included the Anti-Aircraft Artillery. Plans to acquire Spitfires and Lysanders from Britain where thwarted when the outbreak of war forced Britain to cancel all export orders.
After the defeat of Poland, Estonia was forced to accept a Mutual Assistance Pact with the Soviet Union, signed on 28 September 1939. This allowed the Russians to establish military bases in Estonia, which were later used in the Winter War against Finland. On 17 June 1940 the three Baltic States were invaded by Soviet forces. Soviet-style elections were organised and the resulting communist parliament applied for membership of the Soviet Union. This was granted on 6 August 1940. During the June 1940 invasion the Air Defence took no action and subsequently aircraft remained locked in their hangars. The air force became the Aircraft Squadron of the 22nd Territorial Corps of the Soviet Army in the summer of 1940.
On 22 June 1941 Germany invaded the Soviet Union. The speed of the advance was such that Estonia was soon cut-off from Russia by German forces. The 22nd Territorial Corps was ordered to evacuate to Russia but many Estonian personnel deserted and joined the guerrilla forces fighting the retreating Red Army. The Germans were welcomed as liberators when they arrived.