A stunning and unexpected discovery in Guatemala is providing researchers with important new information on the fierce rivalry between two Maya superpowers that raged during the apex of the empire some 1500 years ago. (Discover the top 10 Maya Secrets.)

The find of a broken stone monument at the site of El Achiotal in Guatemala’s western Petén may depict a local vassal lord, or ajaw, installed by Siyaj K’ahk’ ("Fire Is Born"), a warrior-ruler from far-off Teotihuacán, near modern Mexico City. (Who built Teotihuacan?)