In 1213, with the aim of strengthening his power in Brittany, Philip August introduced Peter as administrator of the duchy and tutor of his son, duke Jehan of Brittany. It was Peter Mauclerc who introduced the use of ermines in the Breton coat of arms and came to espouse the cause of his fief's independence with respect to France. While John attempted to regain Brittany in the name of Eleanor, he was defeated in 1214 and finally recognized Alix and Peter. Eleanor ended up in English prison without issue, with her claim never raised ever since.