A series of severe El Niño events occurred between a.d. 500 and 700 that brought torrential rains to the coast, flooding settled areas and destroying crops. Coastal uplift, caused by the earth’s tectonic movement, decreased arable land and rendered canals useless over the centuries. These natural phenomena, combined with overpopulation and warfare, undermined the power of lords, priests, and the social order.
The sacrifice cult appears to have intensified as leaders attempted to placate the gods and demonstrate their powers to their followers. In late Moche times, representational styles similar to those on pottery vessels were used in temple wall art as tools of political propaganda, and new or formerly minor deities rose to prominence.
In the southern highlands, a new cult and culture emerged at the vast city of Huari through conquest of southern and central Peru and through the expansion of religious and economic power. While the north coast was never conquered, it felt Huari’s might indirectly and the old ways of Moche culture were radically transformed between a.d. 800 and 900.
In the northern realm, Moche traditions were reformulated into the Lambayeque culture, while in the south the Chimu arose, eventually conquering their northern rivals. From their vast city and ceremonial center at Chan Chan, the Chimu conquered the old Moche territory and may even have stretched beyond it for a time, only to be conquered by the Inca.