Baron Rouge,
Sadly the Lancastrian "King" Henry VI was on the English throne during the time of French ascendency. He was ineffectual and at times quite mad; the country was governed by his wife (Margaret of Anjou who happened to be French) and her lover, the Duke of Somerset. The complete mismanagement of England during this time led directly to the end of the Hundred Years War and the loss of the vast majority of French possessions, and eventually Civil War - the Wars of the Roses, although Calais stayed with us until the reign of Queen Mary.
As they say in Yorkshire:
"Two things come from the west; bad weather and Lancastrians".