At last I have some time (kind of).
I don't like the idea of a civ winning for managing to do what it historically did or wanted to do. Sure, Rome conquered a huge area and did some amazing things, but the reason this matters is mainly because of what it set into motion. What makes the Roman Empire so interesting and important to me is that culturally, the entire world is still affected by the Roman Empire. Languages, which are one of my favorite subjects, are the best way I can demonstrate this. Latin, which spread with Roman control, has left its mark on numerous languages. If I'm not sorely mistaken, some elements of Latin even ended up in modern Russian (possibly through other European languages). Rome's domination in England left its mark there too, of course, and the English language as I know use it still drips with Latin influence. England went on to independence eventually, and later on created the British Empire. Some colonies in North America broke off from the empire, creating the United States. Today, English-speaking culture from the West has penetrated every country on the planet, at least to some degree. Roman influence is still absolutely everywhere.
All that (most of it unnecessary, I know) is to say that when historical civs did some amazing things, they didn't "win". The things they did just went on to change the world. I know in real life nobody "wins" like in-game, but the feats you win by in-game are all rather fantastic - not real historical events.
Because of this (and following other posts in this thread) I propose the following: civs will each be able to gain special points according to both historical achievements and historical aspirations. For each civ, there will be about 20 points possible. When you hit 10 points, which would be very very formidable, you get a special achievement bonus. For my ever-so-beloved-and-overused Rome example, this bonus could be that Roman culture spreads into foreign cities rather steadily and regardless of Roman cultural strength. This spread doesn't go only to cities neighboring Rome, but to cities neighboring any city with Roman culture in it, and the spread continues forever. This would be somehow realistic, but it would be meaningless in the current game because culture spreads too simply and means too little in small amounts. But that's beside the point. Anyhow, we'd have to design the achievement bonuses to be remotely realistic (or somehow resembling reality) and very useful for surviving and prospering.
Then, if you hit a very high number of points, make it 15 or 18, you win. To do this, you'd have to do way, way better than history. Rome would need to hold onto most of its Empire through AD 1000 (in other words, avert the fall of the empire). Germany would have to win the world wars (yeah, I know they don't necessarily exist in-game, we can work this out later). The Inca would have to dominate South America.
Victory by special points would be awarded for doing the unbelievable. For the merely historical, you'd get a special bonus to help you through the rest of the game.
