[5] Like nearly all the senior Irish judges in that era, he was a client of Gerald FitzGerald, 8th Earl of Kildare, who was almost all-powerful in Ireland for more than 30 years.
Kildare and his faction made the mistake of supporting the claims of Lambert Simnel, a pretender to the English Crown, who was decisively defeated at the Battle of Stoke Field in 1487.
He issued a royal pardon to the great majority of the rebels, including Cusacke, who became Lord Chief Justice in 1490, and his namesake the Recorder.
[1] Henry's policy of clemency had its limits, and his strong suspicion that at least some of the Anglo-Irish nobility were aiding another pretender to the Throne, Perkin Warbeck, led to Kildare's temporary downfall in 1494.
The new Lord Deputy of Ireland, Sir Edward Poynings, undertook a general purge of the Irish judges, including Cusacke, who was replaced by the eminent English lawyer Thomas Bowring.