A lot of the Royal courts of England spoke French, it was seen as sofisticated.Interestingly, there weren't really English or French identities until the hundred years war which was a civil war for the throne of France. The "English" side were those French Viking lads from 1066. The French lads were also French but less Vikingy. The "English" lads lost in the end which is why France is the France we know today. If the "English" French lads had won, England and France would probably be the same country and we'd probably all be speaking French.