Has the capital of Mexico always been city?

The capital of Mexico has not always been Mexico City. Tenochtitlan, located on the same site as present-day Mexico City, was the capital of the Aztec Empire until the Spanish conquest in the 16th century. After the conquest, Mexico City was established as the capital of the Viceroyalty of New Spain, a Spanish colony that included much of what is now Mexico, as well as parts of the United States and Central America. When Mexico gained its independence from Spain in 1821, Mexico City became the capital of the newly independent country.