Collapse of Tiwanaku

From about 600 Tiwanaku, a ceremonial city near the southern shore of Lake Titicaca, had spread its influence across the altiplano and to colonies in the Moquegua valley of southern Peru, where Tiwanaku settlements such as Omo and Chen Chen grew after about 750, and the Azapa valley in northern Chile. Around 1000 Tiwanaku pottery stopped being produced, and within a few decades the urban core of the capital and the Moquegua colony were abandoned; settlements on the Island of the Sun in Lake Titicaca were deserted at about the same time. Parts of the capital show signs of deliberate destruction, though its date is uncertain: monolithic gateways such as the Gateway of the Sun were toppled and broken, and at the end of the Tiwanaku V phase the Putuni complex was burned and its food storage jars smashed. Nearby Lukurmata, once a major ceremonial centre, shrank back into a large village.

Some scholars extend the end of the Tiwanaku state to about 1150, but that date rests only on the raised fields around the lake. The archaeologist Alan Kolata argued that a long drought made the raised fields useless, cutting the food surplus on which elite power rested; refined climate and cultural chronologies have since suggested that the drought began only after the collapse, which supports explanations based on internal social dynamics, while new geological studies again point to growing aridity around the time of the collapse.

Tiwanaku's legacy outlived it: the Mollo culture continued many of its traditions, and it has been conjectured that people dispersing from the collapsing state carried raised-field farming and other influences as far south as the Mapuche lands of Chile between about 1100 and 1300.