Azcapotzalco is one of the 16 municipalities (municipios) into which Mexico's Mexico City is divided. Azcapotzalco is in the northwestern part of Mexico City. The town began in the pre-Hispanic era and was the seat of the Tepanec dominion until the Aztec Triple Alliance overthrew it. After that it was a rural farming area becoming part of the Federal District of Mexico City in the mid-19th century. In the 20th century the area was engulfed by the urban sprawl of Mexico City.