He was born in Ermoupoli, on the island of Syros, on 1 January 1874 to an old shipping family from Psara. His father, Nikolaos, was an industrialist, while his brother Andreas became a politician. He entered the Hellenic Navy Academy, and was commissioned as an Ensign in March 1899. During the 1909 Goudi coup he took an active part as a member of the militaryrevolutionary council. He fought in the Balkan Wars of 1912–13, first as captain of the destroyer, and then as battalion commander of the newly constituted naval infantry regiment during the Second Balkan War. In 1916 Hatzikyriakos joined the Provisional Government of National Defence under Eleftherios Venizelos, and was appointed as captain of the cruiser Georgios Averof, which he commanded during the Greek landing at Smyrna and the opening stages of the Greco-Turkish War of 1919–1922. Following the Greek defeat in the war and the outbreak of the September 1922 Revolution, he became a member of the revolutionary committee and assumed the command of the entire Greek fleet in anticipation of resumption of hostilities with Turkey. Following the peace with Turkey he entered politics and was elected as a representative for Athens in the IV National Assembly, where he became a leading figure in the eventual abolition of the Greek monarchy and the establishment of the Second Hellenic Republic. He served as Minister for Naval Affairs in the Alexandros Papanastasiou cabinet, until his resignation on 5 July 1924, after which he retired from active service with the rank of rear admiral. Hatzikyriakos supported the June 1925 coup of general Theodoros Pangalos, and was appointed again as Minister for Naval Affairs in the new cabinet until his resignation on 8 January 1926. He served again as Minister for Naval Affairs in the 1933–35 Panagis Tsaldaris cabinet, resigning due to his failure to prevent the fleet's participation in the failed coup attempt on 1 March 1935. He then withdrew from public life, and died in Athens on 24 March 1956 at the age of 82. Hatzikyriakos was married to Eleni Gika, and their son was the painter Nikos Hatzikyriakos-Gikas.
