What is the main conflict in Becket, or the Honor of God by Jean Anouilh?

Before his appointment as Archbishop of Canterbury, Thomas Becket's loyalties are to the King. He fights as a soldier in the King's wars, and offers advice to the King. He also helps the King arrange for the Church of England to pay some taxes to the throne, which the Church balks at forcefully. Becket, by the end of Act One, reveals his loyalty is an opportunistic loyalty; he is not exactly sure where his honor lies in life. While in the King's employ, he does serve the King well.