Following an earlier expedition to Yucatán led by Juan de Grijalva in 1518, Spanish conquistador Hernán Cortés led an expedition ("entrada") to Mexico. Two years later, in 1519, Cortés and his retinue set sail for Mexico. Cortés made alliances with tributary city-states ("altepetl") of the Aztec Empire as well as their political rivals, particularly the Tlaxcaltecs and Tetzcocans, a former partner in the Aztec Triple Alliance. Other city-states also joined, including Cempoala and Huejotzingo and polities bordering Lake Texcoco, the inland lake system of the Valley of Mexico. The Spanish campaign against the Aztec Empire had its final victory on 13 August 1521, when a coalition army of Spanish forces and native Tlaxcalan warriors led by Cortés and Xicotencatl the Younger captured the emperor Cuauhtémoc and Tenochtitlan, the capital of the Aztec Empire. The fall of Tenochtitlan marks the beginning of Spanish rule in central Mexico, and they established their capital of Mexico City on the ruins of Tenochtitlan.