There are several theories as to what caused the collapse of the Moche civilization. Some scholars have emphasized the role of environmental change. Studies from glaciers in the Andes reveal climate events between 536 to 594 AD that resulted in 30 years of intense rain and flooding followed by 30 years of drought. This unpredictable weather could have disrupted the Moche way of life and shattered their faith in their religion, which had promised stable weather through sacrifices.

Other evidence demonstrates that these events did not cause the final Moche demise. Moche villages survived beyond 650 AD in some areas.  While there is no evidence of a foreign invasion, at some point they began to fortify their villages, suggesting that they were fighting with one another, possibly the result of climate change, as groups fought for control over increasingly scarce resources.

Tomb belonging to a Moche ruler, Huaca de la Luna.

photo from https://www.archaeology.wiki/blog/2014/07/14/moche-culture-artefacts-unearthed-at-huaca-de-la-luna/