Father Miguel Hidalgo y Costilla was the parish priest of Dolores, Guanajuato, involved with one of a number of conspiracies against the colonial government in the early 19th century.

Fearing his arrest, Hidalgo decided to begin the insurrection early by calling upon parishioners to rise up against the colonial government.

[5][6] The Grito was a call to arms to better the lives of Mexicans, and it immediately attracted the support of the lower classes in the town of Dolores and the Bajío region.

This army passed through the Bajio region of what is now state of Guanajuato, capturing cities such as San Miguel el Grande, Celaya and Irapuato with little resistance.

Many were armed only with primitive weapons such as bows and arrows[4] but the bigger concern for Ignacio Allende was the pillaging, looting and wanton violence that followed the taking of the Bajio cities.

[5] The city of Toluca called upon viceregal authorities for help,[7] which came in the form of contingent of royalist forces under the command of General Torcuato Trujillo.

[8] Trujillo's royalist army took up strategic positions in the Sierra de las Cruces, which separate Toluca from Mexico City.

[8] Command of insurgent forces was put directly under Ignacio Allende, in order to take advantage of his military capabilities.

[8] The battlefield is a site called Los Llanos de Salazar in the current municipality of Ocoyoacac, where more than 90,000 insurgent troops fought.

The battlefield is marked by an obelisk monument constructed in the 1960s to memorialize the event, and which also proclaims Hidalgo as the first "caudillo" of Mexican Independence.

[4] A second monument at the battlefield has huge bronze equestrian sculptures of Hidalgo, Allende, and José Mariano Jiménez on horseback.

Los Llanos de Salazar is filled with food stands and recreational facilities, including in the battlefield area.