One bit of history that Anouilh appears to have appreciated accurately is the fact of Becket's diaconate! In one of the early scenes of the play (watered down in the movie), the king has just presented his new Chancellor to the Archbishop and other Church leaders. While the Archbishop is gracious enough, it is clear that the other bishops in attendance are not pleased, especially when they realize that young deacon Thomas is "switching sides":
Becket: My Lord and King has given me his Seal with the Three Lions to guard. My mother is England now.
Folliot (the bishop of London): A deacon! A miserable deacon nourished in our bosom! Traitor! Little viper! Libertine! Sycophant! Saxon!
I suppose there have been other pastors who have felt the same way about their deacons! One lesson that we can all learn from Becket, of course, is his courage in speaking truth to power, whether that power is found in the structures of the church or in secular authority. May God continue to grant us all the same courage in our own lives and ministry!