He was educated at Malvern College and the Royal Military Academy Sandhurst, and served in the British Indian Army during World War II, where he was a major with the Garhwal Rifles.

[4] Henson began his acting career in 1946 after returning to Britain, in a production of The Dancing Years at the London Casino.

[6][7] He also played in the original West End production of Terence Rattigan's Separate Tables at the St. James' Theatre in 1954.

He had the very rare honour, along with his actor contemporaries Denis Quilley and Michael Bryant, of having a dressing room there named after him.

[11][1] Henson's television appearances included Emergency Ward 10, The Power Game, Sexton Blake, Casting the Runes, The Champions, Follyfoot, War and Peace, Fall of Eagles, the Judge, in Crown Court, and as Sir Horatio Manners in When the Boat Comes In.