The Aztecs are along with the Mayas, the most famous pre-hispanic culture in Mexico. They founded the city of Tenochtitlan in 1325 AD on a small island in the middle of a lake and became the most powerful empire of Mesoamerica in a period less than 200 years. They left a large corpus of archaeological remains that show the development of their society. For their part, the European priests and conquerors who arrived in the city in 1519 AD were surprised by their beauty and the complexity of the Aztec religion. For this reason they wrote numerous chronicles and produced, together with the natives valuable pictorial manuscripts where it is possible to appreciate the history of this town.We will travel through this fascinating society to see the evolution of the Aztecs from their origins as hunter-gatherers until the creation of the great empire that dominated a vast territory. We will see that archaeology becomes the primary discipline to discover the traces left by the Aztecs and to prove that the power, political control, rituals, and richness were sometimes much more amazing than the Europeans described.