 He held the seat until 1758, when he was elevated to the peerage as Baron Brandon in the Peerage of Ireland, and assumed his seat in the Irish House of Lords.He married Lady Elizabeth Fitzmaurice, daughter of Thomas FitzMaurice, 1st Earl of Kerry and Anne Petty.They had seven children, including William Crosbie, 1st Earl of Glandore, Maurice Crosbie, Dean of Limerick, father of the 4th and last Baron Brandon, Mary Ann, who married John Coppinger of Glenville, County Cork and was the mother of Maurice Coppinger, Elizabeth, who married Lancelot Crosbie, and Jane, who married Thomas Mahon and was the mother of Maurice Mahon, 1st Baron Hartland.