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 Lord High 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 derives from the town of Tenby in Pembrokeshire. In 1392 he received a license to study law in England. Somewhat surprisingly (since he can only have been called to the Bar 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, in an act seemingly without precedent, 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.
- Ball, F. Elrington The Judges in Ireland 1221-1921 John Murray London 1926 Vol.1 p. 170
- Brand, P Irish Lawyers and Law Students in Late Medieval England 2000 Irish Historical Studies Vol.32 pp.161-173
- Ball p.170
- Lucas, Charles The Great Charter of the Liberties of the City of Dublin Dublin 1739 p.33
- Patent Roll 1 Henry VI
- Patent Roll 2 Henry VI
- Ball p.170
| Lord Chief Justice of Ireland