Tartiflette Fan - a fair cop, I tend to think of the Duchy of Burgundy and its provinces as an enemy of France in the period but intermarriage caused side changes c.f. Brittany. I was more thinking of the linguistic change, more a result the enforcement of monlithic culture post-revolution.
Asturias - My recollection from studying the 100 years war at university was that many of the English barons refused to fight in and provide taxes, for putting down what was an internal French rebellion, once there was a treaty which established the Kings of England as the the legitimate French Kings. Parallel to today - it is a French War not an English one, we're not obliged to get involved.
I've never understood why George IV gave up the claim to the French throne; I suppose the intention to put 'l'homme qui se dit roi de France' back on the throne made it daft.
Like Lord Raglan many Englishmen still seem to conflate the enemy and the French even when we are on the same side.
We do seem to have drifted along way...