I'll edit in my report later this week (after I write it, just finished the game today ) but I won a conquest victory in 1520 AD. For kicks, I reloaded to the turn before victory to build culture in some newly conquered cities and pop their borders and also was able to win a domination victory in 1520 AD (while still also winning conquest).
For a very short summary: I had been kind of just aimlessly playing until Toku and Justinian decided to both attack me at the same time primarily with HAs, cats, and longbows. Of course, they did that right after I finished research rifling and nationalism I hadn't particularly planned to win by domination or conquest, but at that point said "screw it you guys will pay" capitulated both of them, Ramsses offered to be my vassal, which left only Hannibal left for victory, whom I rolled over with inf and tanks (he research rifling the turn the war started). His capitulation gave me the simultaneous conquest/domination described above.
For a very short summary: I had been kind of just aimlessly playing until Toku and Justinian decided to both attack me at the same time primarily with HAs, cats, and longbows. Of course, they did that right after I finished research rifling and nationalism I hadn't particularly planned to win by domination or conquest, but at that point said "screw it you guys will pay" capitulated both of them, Ramsses offered to be my vassal, which left only Hannibal left for victory, whom I rolled over with inf and tanks (he research rifling the turn the war started). His capitulation gave me the simultaneous conquest/domination described above.