What if Joanna of Navarre had children with Henry IV and Jacqueline of Hainaut had children with Humphrey what would be the consequences of them having children and having Plantagenet heirs.
What if Joanna of Navarre and Jacqueline of Hainaut
Children of Humphrey and Jacqueline would have inherited a continuing claim to Holland and Hainaut, which might or might not have been prosecuted.
I think if the child of Joanna of Navarre is a girl she will marry into the French nobility, if he is a boy he will be just another Arthur or Richard II or he might be an infante in Navarre.Henry IV having children with Joanna of Navarre wouldn't change his succession : Henry V was Henry IV's eldest son and would succeed him. As for Navarra, it works for nothing since Joanna had an older brother (King Charles III of Navarra) who himself had children (Blanche of Navarra, Queen of Navarra and queen consort of John II of Aragon).
Besides the fact it could had people in the successoral order after Henry IV's three sons from his first marriage (Henry V, John of Bedford, Humphrey of Gloucester), I don't see how much History would be changed. This could secure more Lancastrian heirs if the Roses War still shows up though.
Humphrey having children with Jacqueline of Hainaut on the other hand could have butterflies. From what I read, the Yorkists were supporting Humphrey's policies before he died. With Humphrey having an heir, the Yorkists might choose to support Hupmhrey's heir rather than rebel, although claiming the crown for themselves is likely to be tempting.
Another thing is that Humphrey's children would come after Henry VI and Edward of Westimnster in the Lancastrian succession (since John of Bedford died childless), which would change the Roses' War's course if it still happens.
I think if the child of Joanna of Navarre is a girl she will marry into the French nobility, if he is a boy he will be just another Arthur or Richard II or he might be an infante in Navarre.
Bumping this as thought about the effects of a son of Joan and Henry IV last night
A son - probably named John - would likely participate in the wars in France. Assuming he doesn't butterfly things too much any offspring he has will impact lead Lancastrians.
I doubt he'd interven in Navarre as he's too far down the succession but any sons he has could do if their not distracted by their claims to the English Throne.
Any thoughts on who John could marry and what his title would be?
I could see this John being created Duke of Hereford, though Earl of Richmond is a possibility as his half brother John hasn't been created that yet.
As for marriages, could he win over Richard Duke of York by marrying his older sister Isabella?
As side effect it would remove York from claiming the crown and give *Hereford a claim from most lines. That is we could see York supporting Hereford as a replacement for Henry VI.
I also see him marrying Catherine of Valois as her second husband once Henry V dies.
I don't think they'd get dispensation - he is her late husband's halfbrother