John Barnewall, 3rd Baron Trimlestown

However, at the first favourable opportunity the old proprietors, the O'Sullivans, rose and murdered the whole family save one young man, who was absent studying law in England.

He was sworn a member of the Privy Council of Ireland in 1521, and was a supporter of Gerald FitzGerald, 9th Earl of Kildare, whose family still for a few more years retained their 50-year dominance of Irish political life.

His record of loyalty to the FitzGeralds led to trouble for Trimlestown in the next decade when Gerald's son Silken Thomas rebelled against the Crown.

O'Flanagan praises him as an expert on finance as well as law, but adds somewhat cynically that his greatest talent was for looking after his own interests, as evidenced by the substantial grants of lands at Dunleer made to him by the English Crown.

[1][2] In 1536, under the command of the Lord Treasurer, Sir William Brabazon, he made an incursion into Offaly, and drove back the O'Conor clan, who were then ravaging the Anglo-Irish settlements.