Naturally, this is not as easy or as simple as it sounds. While building your empire, you have to maintain each and every one of your cities in the most efficient and productive manner possible, as well as keep a keen eye on your neighbors. After all, they have the same goal you do - world domination. City Management is a critical part of the game. As the population grows, so does its problems.
Wonders are an interesting concept in the game.
They allow the player to have special powers such as longer turns when exploring the oceans to keeping your citizens happy. Trying to quickly take over as much land as possible, I chose to remain a despot throughout the game. While the citizens weren't as happy with the situation as they could have been, I offset my rule with lower taxes and the building of wonders of the world. Choosing a democracy instead, allows your cities to concentrate more on commerce and production and less on war. In fact, your citizens will want to avoid war as much as possible.