Cortés began a siege of Tenochtitlan in May 1521. For three months, the city suffered from the lack of food and water as well as the spread of smallpox brought by the Europeans. Cortés and his allies landed their forces in the south of the island and slowly fought their way through the city. Cuauhtémoc surrendered in August 1521. The Spaniards practically razed Tenochtitlan during the final siege of the conquest.