Most of the French vocabulary now appearing in English was imported over the centuries following the Norman Conquest of 1066, when England came under the administration of Norman-speaking peoples.
After the rise of Henry Plantagenet to the throne of England, other forms of dialectal French may have gained in influence to the detriment of Norman French (notably the variants of Anjou where the House of Plantagenet came from, and possibly Poitevin, the tongue of Eleanor of Aquitaine).