From Seven Myths of the Spanish Conquest, by Matthew Restall (Oxford, 2004), Kindle Loc. 1260-1283:
When the Spaniards under Cortés left the Gulf coast and headed toward central Mexico, native Cempoalan warriors and porters accompanied them, and Tlaxcalans, Huejotzincans, and others later became part of a vast support force that greatly outnumbered the Spaniards. The Huejotzincans continued to fight alongside Spaniards and provide other services as the Conquest stretched out over the 1520s and 1530s. As Huejotzingo’s rulers would inform the king in 1560, “we never abandoned or left them. And as they went to conquer Michoacan, Jalisco, and Colhuacan, and at Pánuco and Oaxaca and Tehuantepec and Guatemala, we were the only ones who went along while they conquered and made war here in New Spain until they had finished the conquest; we never abandoned them, in no way did we hold back their warmaking, though some of us were destroyed in it.”
In fact, the Huejotzincans were not the only Nahuas to fight in other regions of what became New Spain. Montejo brought hundreds of warriors from Azcapotzalco, in the Valley of Mexico, to Yucatan. One Maya account of the Spanish invasion offers a revealing commentary on their use as a vanguard force. Following a series of military encounters in the region, the Spaniards entered the important town of Calkini in 1541 to accept the nominal submission of the local Maya rulers. The description of that ritual by the rulers of Calkini remarks pointedly that the Nahuas—called Culhuas by the Maya after Culhuacan, the town that had once dominated the Valley of Mexico—arrived first. The Maya account also noted that the leader of the Culhuas had been baptized Gonzalo, that their force brought along a herd of pigs (an animal introduced by the Spaniards), and that they were the ones who gathered up the tribute goods offered to the Spaniards.
There is no hint of racial solidarity between Nahuas and Mayas in this account, nor should any be expected. Spaniards lumped different native groups together as “Indians,” but to the Mayas of Calkini, the Culhuas were as foreign as the Spaniards. They were invaders to be repulsed or accommodated, as circumstances allowed, just as if they had come alone as part of the Mexica imperial expansion into Yucatan that never happened but may have eventually occurred had the Spaniards not appeared.
Nor was there a sense of Maya ethnic solidarity in the sixteenth century. In time, Mayas from the Calkini region and other parts of Yucatan would accompany Spaniards into unconquered regions of the peninsula as porters, warriors, and auxiliaries of various kinds. Companies of archers were under permanent commission in the Maya towns of Tekax and Oxkutzcab, regularly called upon to man or assist in raids into the unconquered regions south of the colony of Yucatan. As late as the 1690s Mayas from over a dozen Yucatec towns—organized into companies under their own officers and armed with muskets, axes, machetes, and bows and arrows—fought other Mayas in support of Spanish Conquest endeavors in the Petén region that is now northern Guatemala.