In 1668 he was admitted to Gray's Inn and was later called to the Irish bar.
[1] Under a new charter granted to Kinsale by James II, from 28 February 1687 he held the office of Recorder of Kinsale.
A supporter of James II, in 1689 he was elected to the short-lived Patriot Parliament as a Member of Parliament for Kinsale alongside Miles de Courcy.
[2] He also served as a tax assessor for County Cork.
Following the conclusion of the Williamite War in Ireland, Morrough lost land amounting to a value of £80 per year in the Williamite land confiscations.