Tlatelolco was the market area of Tenochtitlán, the capital city of the Aztec empire, which was founded in 1325. In 1521 Hernán Cortés cut the city off from external food supplies and destroyed the aqueduct that brought water to the city.
The siege lasted seven months. The Spanish and their allied native troops had to fight for every house and street. By August the defenders, under Aztec king Cuauhtémoc, were confined to the formerly great market precinct of Tlatelolco. Cuauhtémoc tried to escape and organize a guerilla war against the invaders but was captured.
Tlatelolco today is the Plaza of the Three Cultures in Mexico City. Documents from three cultures can be seen by overlooking the Plaza: the excavated ruins of the great Aztec pyramid, second largest in the city, the colonial church dedicated to Santiago (patron saint of the conquistadors, who charged into battle yelling "Santiago, and at 'em!") and apartment blocks of modern Mexico.
In 1968 the Plaza of the Three Cultures was the site of a student massacre by government troops that left over 100 people dead. Three inscriptions on the Plaza record the history of Tlatelolco before it was absorbed by Tenochtitlán, the defeat of Cuauhtémoc, and the events of 1968.