It was Archbishop Thomas Becket who died in Canterbury Cathedral on December 29 1170. Becket was, in fact, murdered by four knights, of whom Reginald Fitz Urse was the ringleader. These knights believed that Henry II wanted them to kill Becket, after he said in anger: "Will no one rid me of this troublesome priest?" Whether Henry really wanted them to kill Becket is still the subject of speculation among historians. Whatever the case, the relationship between Henry and his archbishop was at an all-time low by 1170 and had steadily deteriorated since Becket's appointment to the post nine years earlier. Henry hoped that Becket would be his 'yes-man' and support the king's supremacy over the English Church. But, overnight, Becket transformed himself from a "pleasure-loving courtier into a serious, simply-dressed cleric."
The real turning point came in 1164 when Henry tried to make the English clergy sign the Constitutions of Clarendon, an attempt made by Henry to restrict ecclesiastical privileges. As a result, Becket was exiled and spent several years in France. On his return, the pair attempted reconciliation but it failed and, in the following year, Becket lay dead by the altar of Canterbury Cathedral.