Map - Ozumba (Ozumba de Alzate)

Ozumba is one of 125 municipalities in the State of Mexico. Its municipal seat is the town of Ozumba de Alzate. It is located in the southeast portion of the Valley of Mexico, 70 km southeast of Mexico City near the Mexico City-Cuautla highway. The main feature of this area is the Parish of the Immaculate Conception (Inmaculada Concepción) which began as a Franciscan monastery in the 16th century. The entrance to the cloister area contains murals related to the early evangelization efforts of this order. They include scenes such as Hernán Cortés greeting the first Franciscan missionaries in Mexico, the martyrdom of some of the first young converts to Christianity and even a scene where the monks are flogging Cortés. The church itself inside has suffered the theft of a number of its antique pieces. The name Ozumba comes from Nahuatl meaning "over the streams of water". "de Alzate" was added to the formal name in honor of the scientist José Antonio Alzate y Ramirez Santillana who was born here.

The first human inhabitants were hunter-gatherers of various ethnicities. Later, the presence of the Olmecs helped to form the first sedentary agrarian societies. After this, the Nahua eventually became the dominant ethnicity. Most of these Nahuas were of the Xochimilca and Chichimeca tribes. By the 16th century, the area was firmly under the control of the Aztec Empire as a tributary province.

After arriving to the Valley of Mexico, the first Spanish crossed through here on their way to Tenochtitlan. The peoples here allied themselves with the Spanish in 1521 against the Aztecs, an alliance which allowed the people here to suffer less modification of their lifestyles than in other parts of early New Spain. However, this area remained a tributary province with tribute going to the Spanish instead of the Aztecs. The area was divided into encomenderos, but the natives maintained much of their communal farmland despite efforts by hacienda owners to confiscate them. During the colonial period, the main town in this area was Chimalhuacan, generally called Chimalhuacan-Chalco. The village of Ozumba was founded in 1525 by Francisco Atlanlzincuilzin, who was its first leader. Evangelization was done by the Franciscans at the end of the 16th century, when the monastery was most likely established here. The earliest parts of the building date from this time. The first formal church parish was established here in 1606, according to the first records of baptism, which dates from 1621. In this book, which extends to 1650, the baptisms of the indigenous are recorded in Nahuatl and those of the Europeans in Spanish.

Ozumba was under the religious jurisdiction of Tlalmanalco. The bishops and other administrators eventually ceased being monks, with these duties handed over to regular clergy. From 1773 to 1813, a large number of priests were assigned to the parish, which only two staying long term. During the Mexican War of Independence, Morelos’ success in Cuautla forced viceroy Felix Calleja to retreat to Ozumba with more than 200 wounded. After Independence and the erection of the State of Mexico, Ozumba became a municipality in 1825, when the area had about 4,000 inhabitants. "de Alzate" was added to the official name in 1879.

From 1860 to 1870, the area was plagued by a bandit group known as Los Plateados. The first train arrived in 1882, connecting Ozumba with the outside world, especially Cuautla and Mexico City. This contact resulted in the replacement of Nahuatl with Spanish as the dominant language. During the Mexican Revolution, Ozumba was on the border of lands controlled by the government and those controlled by the rebels, leading to significant violence here, including the derailment of the train by Zapatista troops. Ozumba remained mostly in government hands, but the Zapatistas attacked frequently, capturing it for brief periods on two occasions. The violence ended in 1917, and the town has been mostly quiet since. The original municipal palace was demolished in the 1950s and replaced with the current one. The municipal market was constructed in the 1970s. Violence returned to the town when gunmen, presumably from "La Familia Michoacana" drug cartel, shot up municipal president Luis Alfredo Galicia Arrieta's house in the town in the middle of the night in December 2009.