William Brabazon was the Vice-Treasurer and Receiver-General in Ireland for eighteen years. In 1543 he was responsible for receiving the surrender of the Abbeys closed by Henry VIII. In 1543, 1546 and 1549 he was Lord Justice. In 1547 he became an Irish Privy Counsellor. He built the fort at Philipstown and suggested the repair of Athlone Castle. In 1552 he died in Carrickfergus and was buried in Dublin.