Chinautla Viejo was attacked by the invading Spanish in 1525; the first two attacks against the heavily fortified city were unsuccessful. The besieged city received Poqomam reinforcements that were comprehensively defeated on an open field of battle, with the Spanish cavalry being decisive. The capture of Poqomam prisoners allowed the Spanish to discover the location of a cave providing a secret entrance to the city. A third assault broke the month-long siege, allowing the Spanish to take the city. The surviving inhabitants were moved to another settlement and Pedro de Alvarado ordered the city to be burned.