The area was first inhabited by the Otomis, the Mazahuas and the Matlatzincas. Much of this area was marshland fed by the Lerma River. Some claim that the city was founded by the Matlatzincas before the Aztecs arrived, but this is disputed. The area was subdued in 1426 by the Aztec emperor Itzcoatl, when the main settlement was Huitzizilapan. After the Spanish Conquest, the area was divided into encomenderos with this area under the control of Isabel Moctezuma, with Martín Chimaltecatl, the indigenous leader of Ocoyocac having influence. At that time the major settlement here was San Pedro Tultepec as the city of Lerma did not exist. The city would be founded in 1616 as a village.
