I suffered a goverment fall (what a shame!)
Yes, in my first GC playing as Spain. In the 1520s due to constant attacks from France allied with the Turks and constant revolts in southern Spain and other places (specially Zacatecas). I had so far annexed Granada and Napoli.
What happened? Three new countries appeared; Napoli (Napoli, big province in Sicilia), Sicilia (small province in Sicilia) and a huge Granada holding Sierra Nevada, Andalucía, Murcia, Gibraltar and Toledo.
Granada obviously allied herself with Turkey and the north african countries. Turkey took profit of the situation in the Mediterranean and managed to take me off the rest of the Spanish islands.
I still can understand how did I managed to recover from that disaster. Finally I could reannex Granada, which took decades, but never recovered the Italian possesions. Some of the islands were recovered, others weren't.
Pretty shameful but it was my first campaign ... and I saw later the same stuff happen with France (probably due to their insane alliance with Turkey and constant DoWing everybody).