Spanish alliances with other Native American groups proved useful for conquering the Aztecs as the Spanish could now communicate with the Aztecs (Native Americans such as Malinche, a female Indian, picked up Spanish easily and could translate to the Spanish), and they began to learn about local cultures and politics. Some of the these Native American groups also personally hated the Aztecs and gladly fought the Spanish to conquer their empire.
The answer to this question is : Only kings and their relatives could become royalty, while effective military leaders and politicians could become nobles
