OTL, King Henry IV of England had four sons and two daughters. However, his children were strangely unproductive; they produced few children, and only one legitimate male grandchild survived to adulthood -- Henry VI, son of Henry V.
However! OTL, Henry IV's daughter Blanche married Louis, the Wittelsbach Count-Elector of the Palatine. The marriage lasted only a few years, because Blanche died young, but it did produce a single son -- Rupert, Prince-Elector of the Rhine. (Not to be confused with the much later Rupert who fought in the English Civil War.)
Alas, Prince-Elector Rupert died young and left no issue. The Wittelsbach inheritance went to his younger half-brother by his father's second marriage, and the English crown went up for grabs in the Wars of the Roses.
So, the obvious WI: suppose Rupert had survived?
Well, we now have an older Lancastrian heir waiting in the wings as heir-presumptive to Henry VI. Sure, it's descent in the female line -- but it's a stronger claim than Richard of York's. And Rupert will take the Electoral dignity upon his father's death in 1436, when he's 30 years old. This will give him a power base of his own, and a title -- Elector -- that is superior to a mere Duke. (IMS it goes Emperor, King, Elector, Grand Duke, Duke.)
First, does this make the Wars of the Roses less likely? One one hand, Henry VI will still be incompetent and unpopular. On the other hand, in this TL rebelling against him is just opening the way for the Wittelsbach claim.
Second, if there's rebellion against Henry anyway, WI the Wittelsbachs intervene? I suspect that relations with France and Burgundy would complicate things considerably; does anyone know more?
Thoughts?
Doug M.