So the House of Lancaster started thinning out when Henry VI's uncles started dying. And thus moving the duke of York as close to the throne as he was - which was one of the causes of the Wars of the Roses which ultimately saw the house of York triumphant in the person of Edward IV.
However, there could've been more Lancastrians (discounting the Beauforts) between York and the throne. For instance, the Duke of Clarence left a bastard son;the Duke of Bedford's first wife gave birth to a stillborn child in Paris in 1432,; and Jacqueline, duchess of Gloucester birthed a stillborn child in 1424. So how might English history have been different if Henry VI wasn't the only legitimate heir of his generation? Maybe no War of the Roses (or at least the OTL version anyway) in the immediate future?
However, there could've been more Lancastrians (discounting the Beauforts) between York and the throne. For instance, the Duke of Clarence left a bastard son;the Duke of Bedford's first wife gave birth to a stillborn child in Paris in 1432,; and Jacqueline, duchess of Gloucester birthed a stillborn child in 1424. So how might English history have been different if Henry VI wasn't the only legitimate heir of his generation? Maybe no War of the Roses (or at least the OTL version anyway) in the immediate future?