Most Known for their agriculture, cultivating all available land, introducing irrigation, draining swamps, and creating artificial islands in the lakes. They developed a form of hieroglyphic writing, a complex calendar system, and built famous pyramids and temples. Flourished in central Mexico, The Aztec peoples included different ethnic groups of central Mexico, particularly those groups who spoke the Nahuatl language and who dominated large parts of Mesoamerica from the 14th to the 16th centuries. By the early 16th century, the Aztecs had come to rule over up to 500 small states, and some 5 to 6 million people, either by conquest or commerce. Old as 1430-1512 AD, Abandoned at 1512 AD.