The Magenis family, who claimed descent from the lords of Iveagh, became substantial landowners in counties Down and Antrim by purchase in the course of the 18th century. Magenis’s father sat for close boroughs in the Irish parliament and in 1789 became clerk of the ordnance. He supported the Union in exchange for a pension for his life to his eldest son Richard and church preferment for another.
Magenis himself came in for Enniskillen on the interest of his father-in-law in 1790 and of his brother-in-law in 1812. Each time he gave a general support to government, who permitted his son and heir to succeed him as a commissioner of accounts, though they could not make him an efficient one.
