Could Britain keep Normandy after the Hundred Years War? How long could they keep it for? Could the modern world have the United Kingdom of Great Britain, Normandy and Northern Ireland? (or a combination thereof?)
Actually it wouldn't. They could keep England. Scotland and France were military allies at the time.
You'd have to butterfly the Auld Alliance - not easy then and still a bit dicey now (Scots as a whole don't understand the "1000 years of annoying the French" thing.......
you could have the english-burgundinian alliance come out more sucessful...mabye pushing the french back for a while, until all sides decide to compromise...england gives up its claims on the throne, and cedes terrioty in the south, and the french let them keep the northern lot