Following the fall of the centuries-old Toltec Empire in Mexico, the Aztecs – the last of the Nahuatl-speaking people – migrated to the Valley of Mexico, a high south-central plateau. They established the city of Tenochtitlan on a small island on the western shore of Lake Texcoco in 1325 CE.
A century later, Tenochtitlan – later to be known as Mexico City – became the dominant city-state of the Aztec Triple Alliance, which was formed in 1430 and also included Texcoco and Tlacopan. At the height of the Aztec civilization, the city had many temples, palaces and large commercial and residential areas.
Most historical Aztec structures were destroyed when the Spanish arrived in 1519, but many ancient Aztec structures at the Teotihuacan archaeological site remain. The site is a designated United Nations Educational, Scientific and Cultural Organization (UNESCO) World Heritage Site. The holy city of Teotihuacan – meaning the place where the gods were created – is located about 30 miles northeast of Mexico City. Built between the 1st and 7th centuries CE, it is a vast collection of ancient monuments, which include the Temple of Quetzalcoatl and the Pyramids of the Sun and the Moon, which are laid out on geometric and symbolic principles. The Pyramid of the Sun rises to a height of 210 feet.
The Aztec civilization reached its zenith by 1519 and was the most powerful Mesoamerican empire of all time. The multi-ethnic, multi-lingual realm stretched for more than 80,000 square miles through many parts of what is now central and southern Mexico.
When Spanish explorer Hernan Cortes arrived with his troops in 1520, Tenochtitlan’s population was an estimated 200,000 people. By 1521, the Spanish had conquered the Aztecs and founded the Spanish capital of Mexico City on this site. The Aztec ceremonial and political center was rebuilt as the Plaza Mayor, or Zôcalo of the city. Under the Spanish, Mexico City became the center of the country’s political and religious institutions, economy and the home of Spanish social elites.
Shortly after the War of Independence from Spain ended in 1820 after 11 years of fighting, the Mexican Federal District was established, encompassing Mexico City and surrounding municipalities.
Post-independence, Mexico City was captured by U.S. forces during the 1846 – 1848 Mexican-American War and also saw violence during both the French Intervention in the 1860s and the Mexican Revolution, which began in 1910 and ended 10 years later.
In the early 20th century, Mexico City’s population was about 500,000 and it remained the political, religious, financial and cultural center of Mexico. Between 1900 and 1960, Mexico City began expanding, adding municipalities reached by new public transportation systems. As the city expanded outward from its center, it grew upwards. The first 40-story building – the Torre Latinoamericana – was built in the 1950s.
But Mexico City’s population and modernization accelerated in the 1960s when it hosted the Olympic Games in 1968. Its Metro rail system began operating in 1969 and has grown to be the ninth busiest system in the world. The city’s population doubled to nearly 9 million people by 1980, many trying to escape poverty in rural areas.
Today, large numbers of people from rural areas still settle in Mexico City, helping to increase its population to well over 20 million. With population growth, air pollution and other environmental problems have increased. The city’s elevation as well as industry and automobiles can be blamed for much of the environmental damage, although Mexico City’s air quality has improved somewhat due to measures implemented by the government.
In 2016, Mexico City changed its official designation from Mexico Distrito Federal (DF) to Ciudad de Mexico, or CDMX, after two centuries. Like Washington D.C., Mexico City is closely controlled by the federal government, which is based in the city. Under its new status, Mexico City will acquire some of the functions of Mexico’s 31 states, with a constitution and congress holding legislative powers over public finance and security.