isn't France still part of Europe?

It is, it's the UK that left (the EU, not the continent).

The Gelph-Ghibelline conflict was about secular monarchism vs religious authority. Im not sure I see the point you're making.

That the conflict between feudal lords (French aristocrats / Ghibellines) and urban merchants (Guelph burghers / French Girondists) is much older than the French Revolution. The pope and emperor were the figureheads, but the lords and merchants were the power blocs.