In 1940, Prince Michel and his family fled the German invasion and left for New York City,[4] where his mother worked in a hat shop.

[4] Serving in Operation Jedburgh, he was parachuted into Nazi-occupied France as part of a three-man sabotage team (with Maj. Tommy Macpherson and Sgt O.

[4] Dropped on 28 August 1945 by parachute, he was captured the same day by the Viet Minh, who kept him prisoner for eleven months, during which his group of six captives attempted several escapes and were recaptured.

Four of them were killed before the two survivors finally made it back to France due to the French negotiating a ceasefire agreement with the Viet Minh at the Geneva Conference.

A chevalier of France's Legion of Honour, for his services during war, he was also awarded the British Military Cross and the Croix de Guerre.

At the Monaco Grand Prix in 1967, he was a nearby spectator when the Lorenzo Bandini accident occurred: With the help of a marshal he managed to extract the driver from the burning wreck of his Ferrari.