The Otomí were firmly established in the valleys of Toluca, Tula, and Mexico before the first Nahua invasions. Theirs was a sedentary life-style, and they lived in peaceful coexistence with the Olmec and other peoples of the area. The first Nahua who arrived were the Toltec who established themselves by force toward the year 800, founding the city of Tula. The Otomí were incorporated into the Toltec Empire as a subject people. In the twelfth century hunting peoples (generally known as Chichimec) invaded the highlands; they destroyed the Toltec capital of Tula around the year 1200.
After the fall of Tula, the Otomí settled in Xillotepec and Chiapan in the Valley of Toluca. In 1220 they moved east and founded the city-state of Xaltocan to the north of the Valley of Mexico. In 1395 their territory was conquered by the Tepanec. From then on, many Otomí emigrated northeast and east, settling in the provinces of Meztitlan, Tutotepec, Cempoala, and Tlaxcala.
Under Aztec rule, the Otomí became tributaries. The Aztecs did not interfere very much in the affairs of the Valley of Mezquital because it was desertlike and unproductive, and therefore of little interest to them.
When the Spaniards arrived, the Otomí of the Mezquital allied themselves with them, envisoning the possibility of freeing themselves from Aztec rule. During the colonial period, the Otomí played an intermediary role between the Spaniards and the nomadic tribes of the north, thus avoiding serious conflicts and confrontations, especially during the sixteenth and seventeenth centuries. At the beginning of the eighteenth century, silver mining induced the Spaniards to colonize the area and to begin frontal attacks and open warfare against the Chichimec, a war that turned into one of extermination. The Otomí were made to work in the mines, and many fled toward the more arid areas.
Although they were not able to free themselves from servitude under the encomienda (labor-tribute system), the Mezquital Otomí nevertheless benefited from the fact that theirs was not a rich area and so did not attract a large number of White migrants; low population density allowed the Otomí to have extensive landholdings.
The Otomí were involved in the armed conflicts of the nineteenth century, including the War of Independence. Independence did not ameliorate their economic condition, however. Large landed estates were divided into small landholdings that became the property of criollos and mestizos, but the Indians remained laborers.
As a result of the agrarian reform of the 1930s, the Otomí of the Valley of Mezquital were given lands of very bad quality and low productivity, in the form of ejidos. Beginning in 1975, the semiarid lands began to receive drainage and sewage waters for irrigation from Mexico City, thereby becoming productive.