end game diplomacy
The only AI who voted for us was Aeetes, with a net of +10. Dido had a net +7 and Hiram +6. It makes the AIs seem like jerks, but it's consistent what I've heard about vanilla, that you need (approximately?) +8 to get a diplo victory vote from an AI.
Dido was 1 point away from +8. Maybe if we had spammed her with tech gifts just before the vote, we might have gotten a "shared your tech discoveries". Or if we had not invaded Egypt, it sounds like we'd have avoided some of the close borders demerit.
Hiram was 2 points away from +8. Certainly if we had gotten kept him Greek Poly (was he ever in Greek Poly?) that would have turned the -2 into something positive. Or if we hadn't invaded Lydia, we could have avoided his -2 close borders demerit.
So it seems like with the right moves we could have gotten a diplo victory after taking over Iberia or France, maybe even Germany. I'm not trying second-guess our game at all, just analyzing it for anyone who wants to try a diplo in the future.