That isn't actually the most recent save, here it is.
Castille wanted Labourd, and I only wanted it as a naval base, so Castille gave me Gibraltar in exchange.
Anyway, the reason we stopped was because AI Burgundy did TOO good. They attacked France without our permission, and although it only took the stuff previously agreed upon in the partition, it worried us a bit...
Eventually, Castille, Austria, and I all warned Burgundy as a temporary measure until Billy got here. Later, I wanted to vassalize Scotland and Austria wanted revenge on Bohemia, both of which were protected by Burgundy. I made a deal with Austria: if Burgundy DoWs when Austria attacks Bohemia, I would attack Scotland. Burgundy DoW'd both of us and we ended up at war, followed by a (much reduced) France.
We stopped because we wanted to see if Billy would return to the constrains of the Anti-French League (now the Anti-French Region League because of the many released countries.)