The Maya civilization suffered "waves" of war and political instability before its collapse in the 2nd century. The civilization later recovered, but history would repeat itself just a few hundred years later, delivering a final blow, researchers explain in a PNAS study offering a clear chronology of the civilization's demise. It's based on 154 radiocarbon dates from charcoal samples along with data from ceramics at the site of Ceibal in Guatemala which show "similar patterns" of warfare around 75 BC and AD 735, reports the International Business Times. Each was followed by a period of political upheaval, the first of which led into the Preclassic collapse of AD 150-300.
Ceibal then saw a population decline and many other Maya cities were abandoned. But with "the development of dynasties centered on divine rulership," the civilization soon after rallied as power centralized, say researchers at the University of Arizona. However, warfare returned a few centuries later, resulting in a new period of political instability. This one led into the Classic collapse circa AD 800-950, when Ceibal again experienced a population decline, according to a release. But this time, power splintered and the Maya were unable to recover. Archaeologists now hope to survey other Maya sites for similar patterns of decline that may show why the Classic collapse proved fatal. (This Maya pyramid hides two others.)