 He succeeded to the title of Earl of Carnarvon when his father died on 11 September 2001.After the death in 2003 of the 17th Earl of Pembroke, a distant cousin, he also became heir to the Earldoms of Pembroke and Montgomery, held by patrilineal cousin, William Herbert, 18th Earl of Pembroke, and is currently third in line.Lord Carnarvon married Jayne M. Wilby on 16 December 1989, daughter of racehorse owner Kenneth A. Wilby and Princess Prospero Colonna di Stigliano.