Long ago the Kingdom of Aquitaine split from France, and it took a century or two of warfare before the King of France was able to reclaim his lost lands. Unfortunately the King lost most of his army fighting for his claim to Aquitaine (and lost the rest in my Holy War for Brittany) and so rebellions sprung up on his kingdom like mushrooms on a rotting log. Burgundy split off from the Kingdom relatively quickly, probably because the French King was having trouble dealing with the English King trying to put a pretender on his throne. The English won their war, resulting in the French King being bumped off into Aquitaine and the creation of the horrible you see before you.
Not Shown:
The mess of holdings held by rulers of different countries. Aquitaine's capital used to be in Burgundy, for example.
The several unexplainable Orthodox provinces in Burgundy.
England being the King of Jerusalem, which consists of several scattered holdings in the Holy Land.
The HRE being allied with the Byzantine Empire yet again. Damn it.
Other Things of Note:
My thrust up to the north to Holy War all of the tiny countries in Ireland and take Canterbury and its Holy Site from the English.
Why I hate decadent family member who can't be enticed to my court. Assassination just takes far too bloody long to work.
The valiant Flemish surviving as a tiny sliver between France, Denmark and the HRE.