I'm not sure if this is just dumb luck or what, but as the plague was raging along beside my Ottoman Empire, I never caught it until several turns after it was hitting everyone else. Then as I caught it, it died down in the other kingdoms and empires. Not sure what's happening here, nor if it happens to be some coincidence or what.
Speaking of Ottomans, my war with Venice was a stalemale for a century, then they went from Solid/Shaky to an instant collapse after I took one city. Keep in mind this was around the 1590s.
Spoiler :

Speaking of Ottomans, my war with Venice was a stalemale for a century, then they went from Solid/Shaky to an instant collapse after I took one city. Keep in mind this was around the 1590s.