Legends of the Foundation of Mexico
At the period of the conquest of Mexico by Cortés the city presented an imposing appearance. Led to its neighbourhood by Huitzilopochtli, a traditional chief, afterwards deified as the god of war, there are several legends which account for the choice of its site by the Mexicans. The most popular of these relates how the nomadic Nahua beheld perched upon a cactus plant an eagle of great size and majesty, grasping in its talons a huge serpent, and spreading its wings to catch the rays of the rising sun. The soothsayers or medicine-men of the tribe, reading a good omen in the spectacle, advised the leaders of the people to settle on the spot, and, hearkening to the voice of what they considered divine authority, they proceeded to drive piles into the marshy ground, and thus laid the foundation of the great city of Mexico.
An elaboration of this legend tells how the Aztecs had about the year 1325 sought refuge upon the western shore of the Lake of Tezcuco, in an island among the marshes on which they found a stone on which forty years before one of their priests had sacrificed a prince of the name of Copal, whom they had made prisoner. A nopal plant had sprung from an earth-filled crevice in this rude altar, and upon this the royal eagle alluded to in the former account had alighted, grasping the serpent in his talons. Beholding in this a good omen, and urged by a supernatural impulse which he could not explain, a priest of high rank dived into a pool close at hand, where he found himself face to face with Tlaloc, the god of waters. After an interview with the deity the priest obtained permission from him to found a city on the site, from the humble beginnings of which arose the metropolis of Mexico-Tenochtitlan.