when a city in my empire starts to rumble with rebellion I abandon( gift it to an enemy) the city then immediately re enter it and slaughter everyone and get some money as well problem solved I guess its kind of cheap but who says that "I" absolute ruller of my empire cannot slaughter everyone in a city of riotus rebels it happened all the time in this time period.. the only problem is they have bad memories because like 10-15 yrs later they can revolt again

I like it when you have a group of rebellious or near rebellious cities then you do that slaughter everyone move then all the cities around it go back into the green..

yup stuff like that happened all the time