Simplistically put, theBaron's Warwas fought over moneyandpower; the majornoblesofEnglandthought thatKingHenryIIIhadtoo much of the latter andwas exercisingit poorly.
They looked back reverently at KingHenry V, who defeated France in 1415, and with contempt on King Richard III conquered in 1485 by Henry Tudor, who later founded his own dynasty as Henry VII.