The Aztecs were a Mesoamerican culture that existed in modern-day Mexico from the 14th to 16th centuries. The Aztec Empire, a confederation of three large city-states, was formed around the 15th Century. The Aztecs were comprised of several ethnic groups from the region. Most, but not all, were speakers of the Nahuatl language. Much of what we now consider to be Aztec in terms of culture, truly relates more broadly to the whole central Mexican region of that time.