Moctezuma Xocoyotzin ( – 29 June 1520) ] ), variant spellings include Motecuhzomatzin, Montezuma, Moteuczoma, Motecuhzoma, Motēuczōmah, Muteczuma, and referred to retroactively in European sources as Moctezuma II, was the ninth "Tlatoani" of Tenochtitlan and the sixth "Huey Tlatoani" or Emperor of the Aztec Empire, reigning from 1502 or 1503 to 1520. The first contact between the indigenous civilizations of Mesoamerica and Europeans took place during his reign, and he was killed during the initial stages of the Spanish conquest of the Aztec Empire, when conquistador Hernán Cortés and his men fought to take over the Aztec capital Tenochtitlan. During his reign, the Aztec Empire reached its greatest size. Through warfare, Moctezuma expanded the territory as far south as Xoconosco in Chiapas and the Isthmus of Tehuantepec, and incorporated the Zapotec and Yopi people into the empire. He changed the previous meritocratic system of social hierarchy and widened the divide between "pipiltin" (nobles) and "macehualtin" (commoners) by prohibiting commoners from working in the royal palaces.