Sir John Cornwalsh (died 1472) was an Irish judge who held the office of Chief Baron of the Irish Exchequer. His tenure was notable for the fact that he directly succeeded his father in the office, and for his long struggle to hold it against a rival claimant.
He was probably born at Dunboyne in County Meath and later resided at Dardistown in the same county. He was the son of James Cornwalsh and Matilda Rochfort; the Cornwalsh family were originally from Cornwall. His father was Chief Baron, with intervals from 1420 to 1441. John followed his father into the law and went to London to study; he was living at Tower Hill in 1434.[1] He is next heard of " fighting the King's enemies in Ossory" in 1441.[2] In September of that year his father was killed by William Fitzwilliam in a feud over possession of Baggotrath Castle near Dublin.
He was quickly appointed Chief Baron in place of his father, probably on the advice of James Butler, 4th Earl of Ormond, a close associate of his father. However a few weeks later a patent was issued in London appointing Michael Gryffin to the same office.[3] For five years Gryffin's supporters contrived to keep Cornwalsh out of office; finally in 1446 he obtained a declaration that his rival's patent had been obtained illegally.
The conflict no doubt reflected the wider political divisions of the time, but Elrington Ball suggests that there were strong objections to Cornwalsh as a judge.[4] Despite being the son of a long-serving judge and having trained in the law his legal knowledge was thought insufficient. In addition he was a turbulent and unpopular individual: in the 1450s he quarreled with Richard, 3rd Duke of York, the Lord Lieutenant, and his council, and was accused of inciting the citizens of Dublin to rebellion.[5] During York's final Irish Parliament in 1460, Cornwalsh was one of his few opponents, and an Act of Resumption ( forfeiture) was passed against him.[6] After York's death at the Battle of Wakefield no further action seems to have been taken ; Cornwalsh remained in office until his death in 1472, and he was knighted around 1466.
He married Maud Talbot of Malahide Castle.