Peru is currently suffering one of the worst dengue outbreaks on record, with more than 170,000 Peruvians suffering from the mosquito-borne virus and more than 225 dead. The outbreak is driven in part by unusually wet conditions caused by the climate phenomenon known as El Niño.
While many scientists believe the impact of El Niño cycles are increasingly exacerbated by climate change, archaeological evidence shows the climate phenomenon has been severely affecting life in the region for more than a thousand years, with past societies battling its effects with practical on-the-ground engineering as well as spiritual appeals to the gods—appeals that have included acts of ritual child sacrifice unprecedented in world history.
Since 2011, Peruvian archaeologist and National Geographic Explorer Gabriel Prieto has uncovered evidence of mass child sacrifice around Chan Chan, a massive mudbrick city in northern Peru that served as the capital of the Chimú people from the 11th century until they were conquered by the Inca around 1470. More than 250 young victims, whose grisly deaths occurred around 1400-1450, have been located to date. Most were dispatched with a swift cut across the chest and buried in simple shrouds alongside baby llamas.
El Niño and the Chimú
The majority of the Chimú child sacrifices were uncovered in an archaeological site on the Peruvian coast that bears clear evidence of a substantial El Niño event: a thick layer of ancient, dried mud in which the sacrificial victims were buried. Deep mud means heavy rain, and on the arid coast of northern Peru, “such rains usually only come with El Niño,” Prieto explains.
Chan Chan’s population was sustained by carefully managed irrigation systems and coastal fisheries, both of which could have been thrown into disarray by the higher sea temperatures and heavy downpours associated with the recurring climate phenomenon. A severe El Niño, researchers theorize, may have shaken the political and economic stability of the Chimú kingdom. Its priests and leaders may have ordered the mass sacrifice in a desperate attempt to persuade the gods to stop the rain and the chaos.
“Sacrifices are very carefully constructed negotiations and forms of communication with the supernatural,” says Haagen Klaus, a professor of anthropology at George Mason University. “It’s the Chimú interacting with the cosmos as they understood it.”
“This number of children, this number of animals—it would have been a massive investment on behalf of the state,” Prieto adds.
Jane Eva Baxter, an anthropology professor at DePaul University who specializes in the history of children and childhood, notes that the Chimú may have considered their children among the most valuable offerings they could present to the gods.
“You’re sacrificing the future and all that potential,” she says. “All of the energy and effort that’s gone into continuing your family, continuing your society into the future—you’re taking that away when you take a child.”
The need to placate the spirits and stop the El Niño-driven rains may have been an urgent issue for Chimú society, but the mass sacrifice itself appears to have been carefully orchestrated. Hundreds of healthy boys and girls appear to have been brought in from many regions of the sprawling empire, and research is ongoing to determine why they were chosen for their terrible fate. The young llamas—another important resource, culled from state-owned herds—seem to have been specially selected for the event based on their age and the color of their coat.
At the site of Huanchaquito-Las Llamas, where Prieto and his colleague John Verano, a Tulane University biological anthropologist excavated most of the young victims between 2011 and 2018, telltale signs and forensic clues help them reconstruct the sequence of events.
The pattern of footprints and tracks preserved in the dried mud indicates that there was a formal procession to the sacrifice site. The prints of small bare feet, as well as those of four-legged animals being dragged against their will, make Prieto and Verano think the victims were led alive to their graves, where they were killed. A lack of insects in the remains means the children were carefully wrapped in shrouds and promptly buried alongside the llamas.
Did the costly offering bring relief from the flooding rains? It’s impossible to know, but the disturbing event may be a window into the last, desperate years of a dying empire.
“Here you are when you have the most to lose, and you’re giving the most,” Baxter says. “It speaks volumes about where the Chimú were at this moment and in this place.”
Keeping disaster at bay
More recently, Prieto has examined a more than seven-mile-long earthen wall north of Chan Chan which was long thought to be a defensive structure to keep out enemies. Now it appears that wall may have protected against another destructive force—the waves of mud, water, and debris that would rush down from mountains to the east during El Niño rains. Based on radiocarbon dating, the wall was built before 1450, and the archaeologist suspects construction began after an earlier “catastrophic” El Niño event believed to have hit the area around 1100. While protecting agricultural fields and irrigation canals that lay to the west, the eastern side of the wall may have also served as a useful trap for mud and sediment that could be used by the Chimú as fertilizer and building materials.
As archaeologists continue to work in and around the World Heritage site of Chan Chan, more evidence of ancient efforts to tackle the devastating effects of El Niño—both spiritually and practically—may be revealed.
“On the one hand, [the Chimú] were pleasing the gods and showing their people that they were doing everything at their hand,” Prieto notes. “But at the same time, they had real effective technical responses to protect their people, their infrastructure, and their crops. They were working in many fronts at the same time during El Niño. And that's fascinating.”