He was born in Athens on 2 June 1946 to Xenofon Antoniadis, a Hellenic Coast Guard officer.

In 1974–1975 he attended a specialist artillery course in the United States, followed by a course on the OTO Melara 76 mm gun in Italy in 1976.

Commander on 28 September 1979 and served as captain of the vehicle carrier Roussen in 1980–1981, as well as adjutant to the Deputy Defence Minister Antonis Drosogiannis in 1981–1983.

[1] Following a succession of staff assignments, in 1987–1990 he served in the Greek mission to the NATO Military Committee.

[1] In 1994–1995 he served as head of the Landing Ships Command and the Amphibious Operations School, being promoted to Commodore on 17 March 1995.