Prince Antoine escaped from occupied Belgium in February 1943 and joined the RAF in June.

Moved to 160 Wing until detached to Palestine on behalf of the Ministry of Foreign Affairs as UN Truce Observer during the formation of the State of Israel.

Served as Assistant Military Attache in Washington 1952-3, before returning to Belgium as Captain-Commandant to assume command of 9 Squadron flying Gloster Meteor 8s.

Prince Antoine resigned his commission on 1 September 1955 to join the first Belgian Antarctic Expedition under Commandant Gaston de Gerlache (with whom he had trained in the RAF in 1943), leaving Belgium in 1957.

He flew many exploration flights over Antarctica in Austers and Bell 47 helicopters until returning to Belgium in March 1959; also took part in the subsequent Belgian expeditions in 1960 and 1965.