How do you increase the population cap in "Rise of Nations Gold"?

The primary way to increase the population limit in "Rise of Nations" in all game editions is to perform military research at the library. Every time the player acquires another level of military research, the population limit is further increased.

Several other in-game mechanics in "Rise of Nations" can also increase the population cap. Acquiring the rare resource peacocks, for instance, adds 10 percent to the limit, while building the Colossus wonder boosts the limit by 50 percent. The Bantu, one of the game's playable nations, also have a unique trait that adds 100 percent to the current limit and exceeds the maximum limit by 25 percent. The limit can also be increased via a cheat.