Explanation: Due to the... intricacies... of feudal law, the King of England in the High Medieval Period was actually both peer and vassal of the King of France. You see, the King of England held certain lands in France, including the Duchy of Normandy. In this position, he was both King of England (wherein he had no overlord) AND Duke of Normandy (in which capacity the King of France was his overlord).
This led to no end of legal arguments, demands, compromises, and, as one might expect, literal wars between the two polities.
Also, the English court spoke French until the 15th century AD. Hon hon hon!