In the 1200's the nomadic (native) Aztecs began their journey to the Valley Of Mexico.
The Aztecs had a barbarian-like image and therefore were hired as mercenaries (hired soldiers). The Aztecs were forced out of the valley several times over the course of 60 years. Eventually the nomadic Aztecs were told by priests that one day they would build a beautiful capital where they found a sign from the gods.
Valley Of Mexico
As the Aztecs were wandering they came upon an eagle perched on a cactus eating a serpent. They believed this to be a sign from the gods. They immediately settled there on the small swampy island of Lake Texcoco
The no longer nomadic Aztecs started right away to build their beautiful capital foretold by the priests.
The Aztecs had a very precise plan. They built causeways, canals, and roads, that lead to the main city. They also built chinampas or floating gardens where they put soil from the bottom of the lake to make up for the limited space.