Debauched King Henry II (Peter O'Toole) installs his longtime court facilitator Thomas Becket (Richard Burton) as the Archbishop of Canterbury, assuming that his old friend will be a compliant and loyal lackey in the King's on-going battles with the church. But Becket unexpectedly finds his true calling on the ecclesiastical side, and aligns himself against the King's selfish wishes, causing a rift and an eventual showdown not only between the two men, but also the institutions they represent.