Because of William's criticism of King Henry II's policy in Ireland, it has been suggested that William was from Ireland, although this is not known for certain. William was a Benedictine monk at Christ Church Priory and was ordained as a deacon by Becket in 1170. Becket sent William to Reginald, the Earl of Cornwall, in mid-December 1170 as a spy at the royal court, which Reginald was attending. Unfortunately, William was recognized by a royal servant as a member of Becket's household and Reginald sent William back to the archbishop. William was back with Becket by 19 December 1170.
Becket's murder
William was present at Becket's martyrdom, fleeing the scene after the attack on Becket began. William admitted in his writings that he fled to the choir of Canterbury Cathedral when the first blows were struck.
Writings on Becket
William began to collect and edit the stories of miracles that happened at Becket's shrine in June 1172. William was appointed to help with developing the shrine to Becket in Canterbury Cathedral in late July 1172. This collection was given to King Henry II, likely in late 1174 when the king performed his penance for his part in Becket's death. Concurrent with this presentation, William also composed a hagiography of Becket, completed around 1173 or 1174. This work is of great value to historians as it gives a first hand account of the events preceding the murder. This hagiography, or "life", has been called "the closest we have to an official Canterbury Life". It forms one of five biographies that can be grouped together into a "Canterbury Group" that were written by authors closely connected with Becket and Canterbury. It is likely that William was encouraged to write his work because of his eyewitness status to Becket's death. William's biography was written in Latin and is usually given the title of Vita et miracula S. Thomae Cantuariensis. It was edited by James Craigie Robertson and published in 1875 as part of the Rolls Series as well as in the Bibliotheca Hagiographica Latina from 1898 to 1901 as number 8184. William appears to have read two others of the "Canterbury Group" works – the one conventionally called the "Anonymous II", as well as that written by Edward Grim. William's Vita in turn influenced a work by Guernes de Pont-Sainte-Maxence in French verse. The Vita was also included in a conflation of various biographies of Becket into the Quadrilogus II compiled about 1198 by Elias of Evesham at Crowland Abbey.
