 followed by Hernán Cortés, who had brought forces down from Mexico.Much of the conquest took place in the following two decades, first by groups loyal to Cristóbal de Olid, and then by those loyal to Francisco de Montejo but most particularly by those following Alvarado.In addition to Spanish resources, the conquerors relied heavily on armed forces from Mexico—Tlaxcalans and Mexica armies of thousands who remained garrisoned in the region.