A society without writing
The Moche left no deciphered writing, so their society has to be reconstructed from architecture, burials, art and the remains of everyday life. That is why interpretations change. This article looks at how Moche society seems to have been organised and at the main theories of its decline. Famous finds such as royal tombs and portrait vessels are left to one side.
Life in the desert valleys
The Peruvian north coast is one of the driest regions on earth, and farming depends on rivers coming down from the Andes. The Moche built extensive irrigation canals to carry water to fields of maize, beans, squash, peppers and other crops. The canals required planning and labor, and it is likely that the management of water, and of the people who maintained the canals, was one source of power for local rulers. The ocean was just as important: anchovies and other fish from the cold Pacific supplied large amounts of protein.
Llamas were kept as pack animals and for meat and wool. Settlements ranged from small farming villages to large centres with temples, workshops and storage rooms.
Rulers and warrior priests
Moche art shows a rich world of ritual. A recurring scene, called the Presentation Theme or Sacrifice Ceremony by scholars, shows a high-ranking figure receiving a cup, possibly containing blood, from other figures. Burials such as those at Sipan have provided people whose costumes match the figures in the scene, which suggests that elites played these roles in real ceremonies. For that reason, researchers sometimes describe the rulers as warrior priests, combining military and religious authority.
Fighting appears to have been part of ritual. Art shows combat between warriors and the capture of prisoners, who were stripped and led away, and excavations at ceremonial sites have found remains consistent with sacrifice. How much this was ritual theatre and how much actual war is uncertain, and archaeologists continue to discuss it.
Below the elites were farmers, fishers, artisans and laborers. Specialised craft workers, in metalwork, textiles and ceramics, worked at least partly for elite patrons. How rigid these divisions were is hard to say.
The decline
The decline of Moche centres took place between roughly 600 and 800 CE, and it did not happen everywhere at the same time or in the same way. No single explanation is accepted.
Climate shocks
One widely discussed idea links the decline to extreme climate events. El Nino, a periodic warming of the Pacific, can bring torrential rain and flooding to the normally dry north coast, destroying canals and fields, and washing away buildings. Evidence from the Andes, including ice-core records, suggests a long drought in the later sixth century, which may have stressed irrigation systems. Archaeologists have also pointed to layers of flood debris and windblown sand at some sites. Similar arguments are made in discussions of Maya drought evidence in Mesoamerica, though the two regions had different histories.
The theory has a social side: if rulers claimed to control the supernatural forces that brought water and fertility, disasters could weaken their authority. This is an interpretation, and the dating of climate events and of site abandonment does not always line up.
Politics and outside pressure
Others stress political change. Highland neighbours, in particular the Wari state, expanded to the coast in this period, and some Moche centres were reorganised or abandoned, while a large late centre in the north at Pampa Grande shows signs of burning. Internal conflict, shifting trade routes and changes in religion may have contributed. The northern valleys, especially Lambayeque, saw continuity into the Sican culture, so the story is one of transformation as much as ending.
A combination of factors
Most researchers now favour a combination of causes: climate shocks, social stress and external pressure operating together, in different ways in different valleys. The later Chimu kingdom eventually came to dominate the coast, and after the Chimu conquest by the Inca the area became part of the Tawantinsuyu empire.
How to read the evidence
Moche studies rely on radiocarbon results, ice cores and pottery styles, while tree-ring dating, so useful in other regions, is of limited help on this coast. Climate data come from places far from the coast, so connecting them to a specific valley requires care. The Moche did not simply vanish; their descendants and the descendants of neighbouring peoples live in the region today, and some local traditions and crafts, such as the use of reed boats on the coast, are part of a long continuity of life there.