I am being told that at a certain point in time, French was the official langage in the Royal Court of England. French itself being a mix of Latin, Ancient Greek, Franquish, Celt, etc.
Ah yes, when the Normands took over from king Harold the Saxon in Hastings? But those were actually Norsemen descendants, former raiders (« Vikings »). Don’t know how much French they had in them at that point.