Upon doing research for my King Arthur I TL, it came to my attention that the Dukedom of Brittany had been ruled by two other Arthur's in the 14th and 15th Century. Arthur II (1261-1312) and Arthur III (1393-1458). Both had a great deal of Plantagenet blood, but both seemed far enough down the line of succession to ever been considered a legitimate claimant to the crown. Can anyone think of a plausible scenario in which either might have ascended to the throne of England? Please discuss