The reasons for the French victory in the 100 Years War?

The Hundred Years War was a protracted conflict. In it, the parties fought with varying success. In the beginning, the British won, then the French, then again the British. Ultimately, the War of the Scarlet and White Roses began in England, which was essentially an internal war. Because of this, the British could no longer intensively transfer troops to France. Thus, the French were able to return all the lost territories.