Yes.
The king of France, a child I assume (I can't see the pictures) was educated by an Andalusian, or another Arab, and changed culture. Then the Almoravids used an Invasion CB on him, won, and usurped the French king title.
I doubt that could happen in a month, though.
Unfortunately, no. The Kingdom (Sultanate) of France didn't get usurped at all - it simply ceased to exist. There were no obvious major troop movements either.