With Cities, Warfare Came to Mexico

The remains of a 3,200-year-old timber palisade built around a small village in the Oaxaca Valley of Mexico indicate that the earliest Americans had no sooner settled into villages than they began fighting over them, Michigan researchers report today.

New radioisotope dates from the valley indicate that widespread warfare broke out in the region perhaps only a couple of centuries after the native Zapotecs began building clusters of houses together to create shared communities.

Data from other defensive structures in the area suggest that warfare expanded and grew across the valley for more than a millennium, by which time the Zapotecs had established a powerful state and developed the large armies that were maintained until the Spanish invasion in the 16th century.

“What is important is that the work has put radiocarbon dates on every stage in the evolution of war in Mexico from early village to empire,” said archeologist Joyce Marcus of the University of Michigan, who coauthored the report with archeologist Kent V. Flannery in the online version of the Proceedings of the National Academy of Sciences.

The new evidence supports the theory that violence and complex societies evolved together and offers new insights into the beginnings of statehood.

Fighting did occur among simpler foraging societies before the settling of villages, but it was sporadic and seldom led to full-scale warfare, according to archeologist Richard Blanton of Purdue University.

“They could solve problems by simply getting up and leaving,” he said.

But once they had invested the effort in constructing dwellings and other buildings, he added, “it was worth it to stand and fight.”

The discovery was made at the village of San Jose Mogote in the Oaxaca Valley about 250 miles southeast of Mexico City. The site is one of the oldest known settlements in the New World, dating back more than 3,600 years.

Circa 1500 BC, San Jose Mogote had hundreds of residents living in family-size houses of wattle and daub.

The community also had subterranean storage pits that could hold up to a ton of corn, as well as bathhouses and gathering houses for men.

A defensive timber palisade was built around all or part of San Jose Mogote, according to Marcus and Flannery. They say the wall and buildings close to it burned down about 3,200 years ago, presumably as the result of an attack. It “is the oldest directly dated defensive work in ancient Mexico,” they wrote.

The palisade was fairly substantial, supported by two rows of poles embedded in the ground.

“If they were willing to invest that much energy in building a wall, that would imply that there was a great deal of warfare,” Blanton, who also works in the Oaxaca Valley, said.

Fighting reached its peak in the region between 650 BC and 450 BC. By that time, there were 75 to 85 villages in the valley, and chunks of burned daub in sediments from the period are seven times as common as they are elsewhere, Flannery and Marcus found.

Midway through this period, San Jose Mogote was attacked, and its main temple was burned in a fire so intense that its clay walls were reduced to vitrified cinders. Dating the charcoal from a fallen roof beam indicates that the destruction occurred circa 550 BC.

Perhaps as little as 10 years later, a new temple was built adjacent to the ruined one. A narrow corridor separates the two sites, marked by a stone carving that depicts a naked corpse of a captive whose heart has been ripped out. The name of the captive, a rival chieftain, appears in a hieroglyph.

Because the monument is the first example of captive-taking and hieroglyphs in the New World, it was very important to date it accurately. Radioisotope dating of sediments above and below it indicate that the stone dates from about 550 BC, around the time the second temple was constructed.

Flannery and Marcus concluded that by that time, “it had become important to record the sacrifice of elite captives in stone, and one of the earliest uses of writing was to give the captive’s name.”

Because the warfare was so intense, the residents of San Jose Mogote and neighboring communities moved to a more defensible location around 450 BC on a 1,200-foot-high mountain known as Monte Alban, where they built nearly two miles of defensive walls along the more easily climbed slopes surrounding the new city. They also began work on a building with more than 300 carved stones depicting slain captives.

From this fortress, they eventually established an empire that stretched more than 100 miles outside the Oaxaca Valley, exacting tribute from conquered foes with a powerful army led by noblemen and manned by commoners.

They continued their domination for 1,600 years, until they were decimated by disease and the superior weapons of the invading Spanish.