 He was a descendant of Turlough Mór O'Conor, King of Connacht and High King of Ireland.Because of the Penal Laws which restricted the political, religious and commercial rights of Irish Catholics O'Conor left his homeland and moved to Spain where his cousins Alexander (Alejandro) and Dominic O'Reilly, were serving as officers in the Spanish Royal Army.He was established in Aragon.