Prior to deciding on what the new civilizations for the existing architectural styles would be (Spanish, Koreans and Huns) in the Conquerors Expansion, previously considered civilizations had been:
• Western European: Italians.
• Eastern Asian: Khmers and Tibetans.
• Central European: Swiss, Magyars, Slavs and Hasburgs.
In addition, the new architectural style was chosen to be for new world civilizations because the developers found the Aztecs to be cool, had name recognition, and had been defeated by a concatenation of lucky flukes.

Many of these scrapped civilization ideas would later be added into the HD Expansions of Age of Empires II.