It is easy to mock fascination with sacred relics, particularly, in the case of a fragment of St Thomas Becket’s elbow now going the rounds in Britain, when historical events it commemorates strike a discordant note in the modern world. St Thomas’ famous quarrel with Henry II in the twelfth century was about whether clergy accused of a crime should be handed over to the civil authorities, or tried in church courts beyond the jurisdiction of the state. Although still not universally accepted, the reverse is now established good practice in the Catholic Church worldwide – that priests accused of the sexual abuse of minors, for example, should be passed to the secular criminal justice system. But Becket’s contemporary significance lies elsewhere. He was resisting the principle that the Church must obey the state in all things, including clergy discipline and bigger matters.