It was a very, very, very long war.
As posted somewhere else, Catherine just wouldn't make peace without me giving her one of my cities (on a continent in which she had no cities - see the map, I'm yellow, she's red). I wasn't prepared to do this so we fought for 50+ turns while the rest of the world sailed past us science-wise. I say we fought - basically she kept sending invasion forces, which I annihilated each time. Only twice did she get ashore & take a city and in both cases lost it the next turn.
When she finally made peace, we subsequently had two very similar wars, but by that time I had air power and it was a massacre; the last time I brought someone else and their two vassals in, made peace with her, and watched them rip her to bits.
And actually, yeah, quite a lot of cities 'cause I quecha-rushed my neighbour and ended up with 3/4 of a big continent to myself, which I had to fill up (even then Hammurabi came and settled on a one-square headland in the corner). Though when the war wasn't going I was still running ~60-70% science.