I had a ton of warring, ended with domination in the mid 1800's. I started the game by grabbing a few cities + copper. Then I declared on Joao. I didn't want to incur diplo penalties for declaring multiple times so I kept on pushing until I hit feudalism (which I went for pretty early this game). I was in the tech lead for the first half of the game by a pretty significant margin (took MT off of liberalism). After vassalizing Joao, I teched up to curassiers and trebs. I then declared on Augusts as Cathy had vassalized to Cyrus (voluntarily) at this point.
I wanted cathy's shrine but I didn't have the power to take on Cyrus so I went east. Augustus was teching pretty well so I had to be quick. Unfortunately, I suffered a lot of losses as he got up to curassiers as well (I had cavalry/rifles when I finished him off). I ended up using spy revolts to knock out his big cities, then vassalized him after conquering 4 cities. The war was in 2 parts though, because he managed to get peace via the AP at one point so I had to declare twice. But the peace from the AP gave me a chance to build up more troops so it worked out in the end.
After Augustus was gone, I built up some troops and drafted out some rifles. I then declared on Cyrus/Cathy, the other monster in the game. I fought a defensive war initially as Cyrus had a MASSIVE stack. I think it was around 50 units. I used some cheese, by sitting outside one of his cities and constantly hammering it with cavalry while not conquering the city itself. Poor Cyrus sent troops little by little into the city so I killed off the smaller trickles until I shaved off the entire stack eventually. I also used police state (from the pyramids that Joao built) + jails to control my WW. We did most of the fighting in Augustus' former territory so we both accumulated a lot of WW. It was putting a serious dent in Cyrus' teching ability as he had around 10-12
Cathy was holding up pretty well considering she was a vassal - I was hoping she'd unvassalize but I ended up conquering her completely since she refused to unvassalize herself till the bitter end. The AI stupidly ignored rifling as usual, and went up to physics first. Cyrus got MT+rifling pretty soon after that though, so it was a real slug fest for quite some time. I finally got the upper hand when I hit assembly line and started fielding infantry. Cyrus couldn't take them down and I eventually wore him down with the combination of WW and superior units.
I finished the game off by vassalizing Cyrus. My vassals were marginally useful - I didn't want to gift cities back because their capitals were amazing and I didn't want the extra culture pressure against them. Lisbon in particular was a production power house - it was almost as good as my capital post levees.
The funniest thing was that I got enough GG's in the end that I was producing level 5 units without vassalage or theocracy in my capital. 17 XP