11. Why use the double-headed eagle?

Why did the Quauhquecholteca use the double-headed eagle as the symbol of alliance? 

Like the Spanish, Mesoamericans used insignias to denote the name of a family or lineage. They also used symbols in their battle attire to represent the name of their communities. 

For both Quauhquecholteca and Spanish, the eagle was already an essential symbol. The eagle was a primary element in the place glyph used to represent Quauhquechollan: quauh means “eagle” in Nahuatl. Similarly, the image of a double-headed eagle represented the European Hapsburg dynasty and appeared on the coat of arms of the kings of Spain.

Several indigenous communities were granted the right to use the Hapsburg coat of arms in return for their military service. After establishing an alliance with the Spaniards, the Quauhquecholteca adopted the double-headed eagle as a sign of their privileged position in the new colonial system.