What if a surviving independent Brittany, assuming Francis, the father of Anne of Brittany sires a son who sponsors Christopher Columbus.
yes, that what I am looking for.Are we assuming that his voyages go the same as OTL?
By 1492 Brittany is part of France in all but name. Of course, that doesn't mean too much: Columbus was travelling to France the day he received word that Castile would finally sponsor him after so many years. If he had just left a few days earlier the messenger would have failed to catch with him.
But moving to France is not the end of the adventure but the beginning. He'll have to waste a lot of time convincing the French court to sponsor him like it happened in Portugal and Castile, and if he sails from La Rochelle (or Brest, just to meet the OP's suggestion of Britain) then he will land in a completely different spot of the Americas since he's starting way further to the North. (If he lands at all by the way - he's also starting way further to the East. And he packed so few supplies IOTL that the crew was planning a mutiny in the days prior to the first sign of land).
Hmm, if Brittany can provide harbors for an early French exploration project, their little duchy can become very rich.
...if he sails from La Rochelle (or Brest, just to meet the OP's suggestion of Brittany) then he will land in a completely different spot of the Americas since he's starting way further to the North.