Constitutions of Clarendon
The film introduced a somewhat fictionalized plot element not in the original play. Rather than the main conflict between Becket and the King revolving around the Constitutions of Clarendon - as is depicted in the play and as happened in historical fact - the film's dispute between Becket and Henry II centers on the assassination of an accused priest by the henchmen of Lord Gilbert, a nobleman and friend of King Henry, and Becket's excommunication of Gilbert as a result.