Robert Starkey, son of William, was in residence at Dromoland when the rebellion of 1641 began. It seems that he either fled the area or sublet the property. In 1642 Col. Conor O'Brien of Leamaneh, son of Donough and husband of Maire Rua, seized the castle along with a Captain McInerhenny, the leader of the Irish force, who surprised the guards through help of Starkey's assistant Moran. Conor was killed in battle in 1651. His eldest son Donough O'Brien, born to Conor and Máire Rua O'Brien in 1642, was heir to Leamaneh Castle and to the family claim on Dromoland. In addition, Donough inherited large landholdings from his half-brother, William O'Neylan (O'Neillan) (1635–78) of Dysert O'Dea Castle, to whose father Daniel Máire Rua had been married from 1634 until his death in 1639.