Background
FitzMaurice was the son of John FitzMaurice, Viscount Kirkwall, (son of the Honorary Thomas FitzMaurice who was the younger son of John Petty, 1st Earl of Shelburne and younger brother of Prime Minister William Petty, 1st Marquess of Lansdowne) and his wife Mary FitzMaurice, 4th Countess of Orkney, daughter of Murrough O"Brien, 1st Marquess of Thomond and Mary O"Brien, 3rd Countess of Orkney.
