We now have a much better idea of what warfare between Maya city-states was like, and it seems to have been common even during the stable, prosperous peak of Maya civilization.

“[On the day] 3 Ben, 16 Kasew (Sek), Bahlam Jol burned for the second time,” proclaims a hieroglyphic inscription in the thousand-year-old Maya city of Naranjo. The inscribed stela records how Naranjo defeated several rebellious formal vassal kingdoms. According to the modern calendar, Bahlam Jol burned on May 26, 697 CE. More than 1,300 years later, archaeologists working 32km (20 miles) north of Naranjo at a site now called Witzna discovered a stela bearing the location's ancient name: Bahlam Jol.

Burned for the second time

Most of the major buildings in the city—its temples and the palaces of its ruling class—bore the marks of long-ago fire and destruction. “There is abundant charcoal on the floors of the structures as well as burning of the plaster on the walls," US Geological Survey geoarchaeologist David Wahl told Ars. “Several stela and other monuments were intentionally broken to pieces and show signs of burning.” Archaeologists dated the destruction to between 650 and 800 CE.

Meanwhile, Wahl and his team were busy studying sediment cores from Laguna Ek’Naab, a lake near Bahlam Jol. As sediment washes into a lake from the surrounding area, it carries traces of human settlement and agriculture. The clearing of former forests can increase erosion, and charcoal from controlled burns to clear more land falls into the lake, along with pollen from trees and crops. The geoarchaeologists were interested in how that sediment record lined up with information from nearby archaeological sites about how life changed during the Maya Classic Period.

“When they called me to see if my data indicated any changes around 700 [CE], we knew immediately that we had an amazing story,” Wahl said. Around the last decade of the 600s (thanks to a radiocarbon date from a seed), a 3cm thick layer of charcoal marked the sediment core. Other layers of charcoal, from controlled agricultural burns, were much thinner and made of small, fine particles. But this charcoal had fallen in big, blocky particles. It looked like the traces of a whole city burning.

And in the wake of the attack, the sediment core revealed a sudden decrease in the signs of farming, as if people had mostly abandoned the surrounding farmland.

Fallen cities, burned and chopped

The discovery surprised the archaeologists, because most had assumed that during most of the Classic Period—the height of Maya civilization, from around 250 to 950 CE—the Maya didn’t really go in for burning cities and razing cropland. According to conventional wisdom, warring Maya kingdoms didn’t resort to that kind of total warfare until what’s called the Terminal Classic Period, from 800 to 950 CE. During that last century or two of Maya civilization, environmental stresses, like droughts, seem to have eroded the stability of the Maya world, leading to a sharp escalation in conflict between kingdoms.

Of course, inscriptions all over the Maya Lowlands describe cities burning, “falling,” or being “chopped” even at the height of Maya prosperity and stability. Archaeologists have long assumed those terms refer to carefully targeted, almost ritualistic kinds of violence, like burning a city’s central temple or kidnapping its ruling family. That’s because images from several Maya sites show victors executing captive royalty and burning temples but not laying waste to whole cities and their surrounding farmland.

No physical evidence of larger-scale destruction shows up in the archaeological record until after 800 CE, when it mostly occurs in a region of northwestern Guatemala called Petexbatun. “The lack of any real evidence of what warfare looked like during the Classic period has led to many of the theories that warfare was limited and ritualized,” Wahl told Ars.

In part, we owe that idea to the humidity and warmth of the tropics, where wood and other organic matter—the kinds of materials that would have made up ordinary people’s homes and shops—don’t last long. “Most of the archaeological record is based on stone monuments, ceramics, etc., and reflects the elite component of the society,” Wahl said. “With archaeological data it is very difficult to extrapolate to the broader impacts beyond the elite class.”

The evidence at Bahlam Jol suggests that we should take the implications of Maya war inscriptions more seriously (and probably the rulers of Bahlam Jol should have, too). At Naranjo, the inscription refers to Bahlam Jol’s fate as “puluuy,” or “it burned.” The same turns up in many other descriptions of Maya conflict, and now archaeologists have reason to believe that it refers to a city-wide conflagration.

Other words, like “ch’ahkaj” (chopped) or “jubuuy” (fallen), also show up pretty commonly in inscriptions from the Classic period. It’s possible that total warfare may have much more in common in the Maya lowlands much earlier than archaeologists thought. “As with many aspects of Maya civilization, we continue to realize that the pre-Hispanic Maya were more complex than previously thought,” wrote Wahl and his colleagues in their paper.

If at first you don’t succeed, rebuild and try again

The rulers and people of Bahlam Jol had (according to the Naranjo inscription) already rebuilt the city after one burning, and in the early 700s CE, in the wake of Naranjo’s fiery retribution, they rebuilt again. Inscriptions at the site reveal that the royal family survived the devastating attack, and the dynasty lasted about another century. They rebuilt the royal palace and erected two stela, which told later archaeologists the city’s name and let them link it to the inscription at Naranjo.

And life went on, in a way, though the farmlands around Bahlam Jol were never again as populous or as densely farmed as they had been before the war. Traces of pollen, erosion, and occasional burning are much sparser in the later layers of sediment from Laguna Ek’Naab, but they’re still there. That suggests that some farmers still hung on for several more centuries.

Although the razing of 697 CE marked the decline of Bahlam Jol, Wahl’s sediment core suggests the city may have endured other attacks during its long history. Three other thick layers of charcoal stand out in the sediment core—none as heavy as the one marking Naranjo’s attack, but all thick enough to be out of the ordinary. And their dates line up with other conflicts in the area.

“We don’t have the “smoking gun” of a written account, but we are currently assessing ways to explore the possibility that these events may represent military activity,” Wahl told Ars Technica. His team is also using the lake sediment cores to study whether drought played a role in the eventual abandonment of the Maya lowlands.

Nature Human Behavior, 2019. DOI: 10.1038/s41562-019-0671-x; (About DOIs).