The area remained ruled by the Aztec Empire until 1521, when the Aztecs fell to the Spanish when Azcapotzalco had a population of 17,000. From 1528 to 1529 the Dominicans were in charge of the evangelization of the area under Fray Lorenzo de la Asunción, who built churches of over the former Tepaneca ceremonial center dedicated to the Apostles Phillip and James. Despite accounts that Lorenzo de la Asuncion defended the indigenous against their Spanish overlords, during the 16th century, the indigenous population of the area fell from 17,000 to about 3,000 due to mistreatment and disease.