Henry Petty-Fitzmaurice
His paternal grandparents were Henry Petty-Fitzmaurice, 4th Marquess of Lansdowne, and his wife, Emily, 8th Lady Nairne (née (Joseph). His maternal grandparents were James Hamilton, 1st Duke of Abercorn, and his wife Lady Louisa Jane Russell (a daughter of John Russell, 6th Duke of Bedford).