After William II's sudden death in 1100, Thomas arrived too late to crown King Henry I, and died soon after the coronation.

[7] He was a canon and the treasurer of Bayeux Cathedral as well as a member of Duke William's ducal clergy before the Norman Conquest of England.

[8][12][13] Although this settled the issue between Thomas and Lanfranc, it was the beginning of the long-running Canterbury–York dispute over the claims of Canterbury to have jurisdiction over York.

[14] The next year both archbishops travelled to Rome for their palliums,[a] where Thomas took advantage of the opportunity to ask Pope Alexander II to decree that the sees of Canterbury and York were equal.

Thomas also sought to have the pope declare that the midland sees of Worcester, Dorchester on Thames,[b] and Lichfield – all south of the River Humber – were part of the Archdiocese of York rather than Canterbury.

[12] The 12th-century chronicler Eadmer, a monk at Canterbury, wrote much later that Thomas had resigned and surrendered his archiepiscopal symbols, but they were promptly returned to him by Lanfranc on the pope's orders.

[3][18] This meant that the disputed bishoprics were taken from the province of York, an outcome that probably had the support of the King, who aimed to prevent the separation of the north from the rest of England.

[17] All of these decisions were ratified in the Accord of Winchester that year, witnessed by the King and the papal legate, or representative of the pope, as well as many bishops and abbots.

[24] Wulfstan often performed episcopal functions in parts of the diocese of York during the 1070s for Thomas, especially in areas that were still in turmoil after the conquest.

[25] Thomas reorganised the cathedral chapter during his archiepiscopate, establishing a group of secular canons with individual prebends to provide the clergy with income.

[27] Archdeacons were responsible for aiding the bishop or archbishop with his episcopal duties, collecting revenues, and presiding over some judicial courts.

[33] After the death of the Conqueror, Thomas was loyal to the third son, William Rufus, who had inherited England instead of the eldest brother, Robert Curthose.

[c] Thomas supported Rufus despite a rebellion led by his old mentor Odo of Bayeux, and the Archbishop accompanied the King on his campaigns to put down the revolt.

[35] Thomas attended the subsequent trial for rebellion in 1088 of William de St-Calais, Bishop of Durham, who had sided with Odo.

The first of these occasions was over the dedication of Remigius de Fécamp's new cathedral at Lincoln[3] and the second concerned the consecration of Anselm as Archbishop of Canterbury.

[39] Herbert de Losinga was appointed a papal legate in 1093 by Pope Urban II to investigate the matter of Thomas' profession of obedience to Lanfranc.

[49] Thomas did not concern himself with the church–state issues surrounding the Investiture Crisis, but he was tenacious in defending the independence of York against the efforts of Canterbury to assert primacy over the whole of England.

[50] Later authors, including William of Malmesbury and Hugh the Chantor, praised Thomas for his generosity, chastity, elegance, and charm.