O'Brien, Cornelius (c.1782–1857), landlord, lawyer, and MP, was born at Birchfield, Liscannor, Co. Clare, the third son of Henry O'Brien of Birchfield and Ennis and his wife Hellen O'Callaghan, of Kilgorey, Co. Clare. Educated in Ennis, he entered the King's Inns in 1803, qualified as…