I don't know if this is all that uncommon of not, but I just won the game without ever having been at war with any of the other player factions.
This was a 10 player game on a medium map (I created factions for Capitar and Umbar, and played Umbar), Difficulty levels were Challenging, all other settings the normal defaults.
In a nutshell, the game went as follows: In the initial scramble for territories, I found myself next to Krax. I was closer to all the city sites in the area, and I grabbed them all; I was able to form three new cities, and he zero. So, I had a large and continuous power advantage over him early in the game, and he never gave me any trouble. We were always Close, and eventually tech permitting, Allies.
I discovered I had Gilder as my neighbor to the northwest, and behind him on a larger subcontinent were all the other players except Yithril (and Altar, which I'll get to in a bit). None of those ever were able to get a power advantage over me, so they all drifted in to a Close relationship, after the usual routine of signing non-aggression pacts and trade treaties with them at every opportunity. All became Allies as soon as we got the ability.
They warred in desultory fashion amongst each other throughout the game, and although a city would change hands on rare occasions (maybe about three times, the entire game), no player eliminated another player. We began with 10 factions, we ended with 10 factions.
Yithril was interesting. They were large peninsula to the south of me, reachable only through a long and narrow isthmus. And the north end of the isthmus was my territory, so the only way they could reach the other players was to go through me. Early on, when we were close in power, I got a non-aggression pact and trade treaty with him. But then he got his Juggernaut technology, and his power began to skyrocket. When the NA pact lapsed he had a 2-1 power advantage over me (and 4-1 to 10-1 over all others), and it became cost-prohibitive for me to have any more diplomatic dealings with him.
But he never declared war on me, oddly enough. He did declare war on every other player while we had our NA pact in force, and did at one time send a tiny force (his Sov and one warg unit) through my territory as a scouting force I guess. But after our NA pact lapsed he neither declared war on me even though we became Unfriendly), nor prosecuted the wars vs. all the other players (which became impossible due to the lack of access through my territory). He basically just sat in his two-city peninsula (there was a third city, but it looks like it got destroyed by monsters early on and never rebuilt) and did nothing.
(I think maybe the fact that he had all these other pending wars on his plate discouraged him from declaring war on me ... ?)
Anyways, eventually Gilder and I managed to clear a big swamp wilderness to the north, and I was finally able to plant new cities. Then my growing army overtook whittled down Yithril's power lead, and finally surpassed him. He quickly drifted to Close, then I was able to Ally with him and win the game.
But not quite. The game did not end. Puzzled, I began to check and make sure everyone was Allied ... and discovered that there was one player I never encountered, and thus I had no relations with - Altar. I searched the entire contiguous land mass, and they were no where to be found.
It turns out they were hidden on an island far to the northwest (!) and I only found them by laboriously searching the seas with Raise Land and Ogre scouts. Once I did, I immediately intimidated them diplomatically; they went from Neutral to Close in one turn, then next turn they were my Ally. Boom, game over.
The search for the Lost Civilization of Altar was the only real frustration in this game, which wasted about 20-30 turns. It was a completely bloodless victory (if you don't count the non-player monsters and quests).
On one hand, it feels like this was too easy. But OTOH, I'm sure without Diplomatic victory on, I would have eventually won via one of the other methods, I managed to get that much of an expansion advantage over the other players in the early and mid game, such that if I did have to slog it out via wars I would have prevailed (unless they would have all ganged up on my at once, which I notice the game does not tend to do to the front-runner ... there does not seem to be any "Bad Boy" concept in this game). The Diplomatic victory was a just a convenient recognition of that reality.
