William Tynbegh

William Tynbegh, or de Thinbegh (died 1424) was an Irish lawyer who had a long and distinguished career as a judge, holding office as head of all three of the courts of common law and as Treasurer of Ireland. His career is unusual, by modern standards, in that he left the Bench to become Attorney General for Ireland, but later returned to the Bench.

He was born in Ireland to a family of Welsh origin: his surname is a derivation of Tenby. In 1392 he received a licence to study law in England. Somewhat surprisingly (since he can hardly have been called to the Bar more than a year or two previously) he was appointed Lord Chief Justice of the King's Bench for Ireland as early as 1396 and Chief Baron of the Irish Exchequer in 1397. In 1400 he resigned from the Bench to become Attorney General. He is mentioned again as Chief Baron in 1405 and 1417; in 1412 he received a commission to act as justice of the peace in Dublin and the adjoining counties. He returned to the Court of Common Pleas (Ireland) as Chief Justice in 1419 and again in 1424. In 1420 he witnessed the charter by which King Henry V guaranteed certain liberties and privileges to the Mayor and citizens of Dublin.

He was appointed Treasurer of Ireland in 1421. He was still living in March 1424 when he ordered the Archbishop of Dublin to make a grant of land; but he died later the same year.