- Capital of Mexico: founded in 1325 as the Aztec capital of Tenochitlan. 1521 conquered by Spain; 1821 independence and capital of the Republic of Mexico. Urbanization depicted as of 1847 shown in black. The city originated in the Anahuac basin in an island in Lake Texcoco, no longer existing. Sources: "Map of the Valley of Mexico and the Surrounding Mountains," by Goldsborough Bruff; New York, Published by John Disturnell, 1847; historic extent superimposed on Oficina del Plano Regulardor: Departmento Del Distrito Federal, UC Berkeley: Earth Science Map Collection G4414.m6 G45 1953 M4 1524-1953.) Population 18,735,000 (UN 2005), 19,460,000 (UN 2010).