In 2000 the New York City metropolitan area was slightly larger than Mexico city, with 21.1 million people.
Mexico City had 18.1 million people in its metropolitan area and was ranked the fourth largest city in the world, after Tokyo, Japan; New York City; and Seoul-Inchon, South Korea.
In 2010, Mexico City was the second largest city in the world, and as a global city, it is one of the most important financial centers in America.
Mexico City was the eighth richest city in the world in 2008, and had a Gross Domestic Product of almost $390 billion U.S. dollars.
The city was originally built on an island of Lake Texcoco by the Aztecs in 1325, and was almost completely destroyed in the siege of 1521.
Mexico City served as the political and financial center of the Spanish colonial empire, and after independence from Spain was achieved, the Federal District was created in 1824.