His mother was Ismay Dillon, daughter of Sir Bartholomew Dillon, Lord Chief Justice of Ireland and his first wife Elizabeth Barnewall; after his father's death she remarried Sir Thomas Barnewall of Trimlestown.
Despite his family's history of Catholicism, the Baron was also reluctantly involved in the Elizabethan era religious persecution of the strictly illegal and underground Catholic Church in Ireland.
The Baron explained the imminent danger to both himself and his family and in return, the Archbishop voluntarily agreed to travel back with him and surrender at Dublin Castle.
[3] Meanwhile, despite his own militant Protestantism, the Earl of Ormond was greatly offended and distressed at the trickery used in the arrest of a guest in his house, and afterwards he did everything he could in vain to rescue Archbishop O'Hurley from the executioners.
He was one of the leaders of the opposition to the policies of Sir John Perrot, the Lord Lieutenant of Ireland, in the 1580s.