Born Jacob des Bouverie, he was baptised on 14 October 1694 in St Katharine Cree, London, the son of Sir William des Bouverie, 1st Baronet and his second wife Anne Urry.
He was created Viscount Folkestone and Baron Longford on 29 June 1747 and was appointed one of the deputy lieutenants of Wiltshire on 8 November 1750.