After his secondary studies in Thessaloniki, he went to Germany for higher studies in Strasbourg 1909-12 and fought as a volunteer in the Balkan wars. On his return he became involved in politics. He became one of the most important members of the Liberal party. He married Virginia Delta, daughter of Penelope Delta, who introduced him to Eleftherios Venizelos, forming a close friendship. As a result, he was actively involved in the“National Defence” movement in 1916, which granted sovereign rights to the troops of the Entente and in the creation of the second government in Thessaloniki.

Zannas, a former reserve lieutenant of the air force, was later the organiser of the Military and Naval Aviation (1931) and then Minister of Aviation. He also briefly served as Minister of Agriculture (1932). Eneplaki in the 1935 movement. He was elected MP forThessaloniki with the Liberals in 1933, 1936 and 1950. In 1942 he was arrested by the Italian occupiers and sent to a concentration camp in Italy. After liberation, Zannas was president of the Greek Red Cross (1945). He wrote historical works: The Macedonian Struggle. Memories of the First World War. The Occupation. etc.