He studied at the Naval School. He served in the Naval Cadet School , Artillery School and Port Smooth Staff School and reached the rank of Rear Admiral (1947). He fought in the Aegean during the Balkan Wars and in World War I as a second lieutenant. In 1920-21 he became a professor of artillery at the Naval Cadet School and the War College . In 1928 he was promoted to Destroyer Squadron Commander. In 1930 he became aide-de-camp to the President of the Republic. In 1935 he was demobilized and sentenced to death because of his participation in the democratic Venizelist movement, he was pardoned and reinstated. With the declaration of war (1940) and at his request he returned to active service . He was sent as a naval attaché to England (1941) and became D / D of the 2nd World A / T. In 1943 he became a vice admiral and commander of the fleet in the Middle East .

He took part in many important operations in the Mediterranean, Sicily, Tunis, Dodecanese. Alexandris was given part of the Italian fleet. Finally, he served as chief of the Naval Station and Naval Station. He served as a naval commander and commander of the Naval Command. For a time he became Minister of Merchant Marine (1945). He was honoured with medals and other distinctions, briefly mentioning, Silver Cross 1915, Gold of George I, Medals of Greek-Turkish and Greek-Bulgarian 1913, English Order of Brigadier, Cross of the North-North, Cross of Brigadier George I. He wrote historical works and many studies on the Seafaring of the Greeks. He was honoured by the Academy of Athens (1930 & 1955) for his writing.