Aeronaut, the first Estonian airline, was founded on 22 March 1921. The first plane of the company was a rented Sablatnig P-III, which operated postal flights to Finland. In August of the following year, the first of six Sablatnig P-III aircraft built under licence by Dvigatel was completed; the rest were completed next month. In 1922, Aeronaut also built a reinforced concrete hangar at Lasname Airport.