He was the son and heir of Charles Christopher Courtenay, 17th Earl of Devon (1916–1998) by his wife Venetia Taylor (died 2001).

The ancient Earls of Devon of Tiverton Castle were extinguished in the 15th century during the Wars of the Roses, but the title was revived soon after for close cousins who successively died without male progeny.

Born the day after Exeter was bombed during the Baedeker Blitz and while his father was away in North Africa with the Coldstream Guards, it was reported that his sisters and household staff had been hiding in the cellars while his mother insisted on giving birth in the state bed rather than evacuate.

[1] After succeeding to the family titles in 1998, Devon was the last of the hereditary peers to make a maiden speech in the House of Lords.

[4] The 18th earl greatly improved the estate, expanding its farmlands from 400 to 2,000 acres and reviving the 18th-century gardens and deer park.

He also ran horse trials from Powderham, managed one of the leading herds of cattle in South Devon, and successfully sued the Crown to regain the family's medieval land rights on the foreshore of the estuary of the River Exe.

[1] The earl also worked as the land agent for other estates, including Blickling Hall in Norfolk, Broughton Castle in Oxfordshire and Monteviot House in Roxburghshire.