The first President of the Hellenic Republic was Pavlos Kountouriotis, an Admiral and supporter of Venizelos who resigned after a coup d'etat in 1925. He was succeeded by the coup's leader General Theodoros Pangalos, who was likewise deposed by the military 5 months later after embroiling Greece in the War of the Stray Dog. Kountouriotis was reinstated and reelected to the office in 1929, but was forced to resign for health reasons later that year. He was succeeded by Alexandros Zaimis, who served until the restoration of monarchy in 1935.
Despite a period of stability and relative prosperity under the last government of Eleftherios Venizelos in 1928-1932, the effects of the Great Depression were severely felt, and political instability returned. As the prospect of the return of the monarchy became evident, Venizelist officers launched a coup in March 1935, which was suppressed by General Georgios Kondylis. On October 10 1935, the chiefs of the Armed Forces overthrew the government of Panagis Tsaldaris, and Kondylis declared himself Regent. He abolished the Republic and staged a plebiscite on 11 November which resulted in return of the monarchy, in the person of King George II.
The Junta had already held a staged plebiscite to abolish the monarchy on 29 July 1973, and passed a new Constitution which established a presidential republic (with the junta principal Georgios Papadopoulos as President). This short-lived attempt at controlled democratization was ended by Brigadier Dimitrios Ioannides' overthrow of Papadopoulos in November 1973. The Republic was maintained, but was nothing more than a façade for the military regime.
After the fall of the regime and the return to civilian rule in August 1974 however, the legal and constitutional acts of the junta were deemed invalid, and a new plebiscite was held on December 13, 1974, which finally abolished the monarchy. A new Constitution was adopted that declared Greece a parliamentary democracy. This constitution, revised in 1985 and 2001, is still in force today.