He followed his father into the British film industry in the 1970s, working as location manager on A Bridge Too Far and associate producer of Death on the Nile and the television serial Quatermass.

He also succeeded to the Knatchbull Baronetcy, of Mersham Hatch in the County of Kent, in the baronetage of England.

He is a descendant of Queen Victoria, whose second daughter Princess Alice of the United Kingdom was his maternal great-great-grandmother.

[4] Mountbatten is married to Penelope Meredith Eastwood[5] (born 16 April 1953), a daughter of Reginald Wray Frank Eastwood (1912–1980), a self-made millionaire former butcher who founded the Angus Steakhouse chain, and Marian Elizabeth (1926–2020), née Hood.

[6] They were wed on 20 October 1979 at Romsey Abbey, less than two months after the IRA murdered his 79-year-old maternal grandfather, Louis Mountbatten, 1st Earl Mountbatten of Burma; his 14-year-old younger brother, Nicholas Knatchbull; and his 83-year-old paternal grandmother, Doreen Knatchbull, Dowager Lady Brabourne.