His father was the younger son of Robert King, 1st Viscount Lorton and inherited from him the estates of Rockingham, County Roscommon, and Newcastle, Ballymahon, County Longford.
The patriarch of his family was the younger son of Robert King, 1st Viscount Lorton, and he succeeded in inheriting the properties of Rockingham, County Roscommon, and Newcastle, Ballymahon, County Longford from his father.