Over what people did Montezuma reign as emperor?

Montezuma was the emperor of the Aztecs. The Aztecs were a very powerful civilization in Middle America when the spanish Conquistadors came and started taking their land from them together with taking away their rich as well.

It was the "Aztec people" whom Montezuma reigned over as emperor, although it should be noted that he was eventually toppled and defeated by the Spanish Cortes.