archaeology.org 29Rivers snaking down from the mountains provided the Moche
with just enough water for farming, and people clustered in
valleys around the precious freshwater flow, digging irrigation
ditches to grow crops such as maize. But, at nearly any moment,
the environment could turn on them. Every few years the sur-
face of the Pacific Ocean off South America would grow warm,
a phenomenon now known as El Niño. This seemingly subtle
change can wreak havoc on weather patterns worldwide, bring-
ing drought to some parts of the globe while drenching others
with heavy rains. In Peru’s coastal desert, an El Niño means
torrential rain. In the first millennium a.d., rivers would flood,
adobe houses would wash away, and the usually life-giving valleys
would be transformed into death traps.
Balanced on this razor’s edge, the Moche turned to reli-
gion to keep them safe. The most powerful people in Moche
society were priests and priestesses, and their authority was
based on their ability to communicate with and even embody
the gods. On platforms atop huge adobe pyramids, priests
dressed as deities—named Wrinkle Face and the Decapita-
tor by archaeologists—would slit captives’ throats and drink
their blood from goblets. Detailed depictions of such scenes
appear again and again in Moche art, and some elites were
even dressed as gods when they were buried. Moche priests
and priestesses “were like demigods,” says Michele Koons, an
archaeologist at the Denver Museum of Nature and Sciencehow the Casma ran their government and what commoners’
daily lives were like. She quickly realized that, unlike their pre-
decessors the Moche, the Casma didn’t build grand pyramids
or make ornate art. Casma pottery, architecture, and jewelry
were unfussy, even humble. This, Vogel realized, might have
been an adaptation to the changing climate and the political
uncertainty it sowed. “We know there were periods in Peru’s
past when there were short-term and sometimes very long-
term changes in the weather,” says Jeffrey Quilter, an archae-
ologist at Harvard University who studies Peru’s north coast.
“The perennial question, whether it’s Peru or anywhere else,
is, to what degree do climatic events have long-term impacts
on cultures?” Casma, unrecognized as a significant state until
Vogel’s work, apparently offered a beacon of stability during
what scholars have considered a tumultuous time. Vogel has
discovered that while the Casma weren’t great conquerors and
didn’t leave behind extravagant tombs, they did something
much more impressive—in the face of climatic and political
chaos, they survived, and even thrived.T
he Casma way of life was a sharp departure from that
of the Moche, who dominated the north coast of Peru
from about a.d. 200 to at least 650 , and until 900 in
some areas. For these people, survival in one of the world’s most
arid environments depended on staying on the gods’ good side.A pile of stone rubble stands in a walled public plaza at El Purgatorio. It would have been the scene of frequent feasts thrown
by Casma rulers in order to maintain social order during trying times.