there were protests against the expulsion of the Jesuits by the Spanish Crown. These were put down with extreme force, but they spurred conspiracies, and groups organizing against colonial rule, especially in San Miguel el Grande and León.
Numerous plans were made, but few were carried out or had impact until 1809. In that year, a group consisting of Miguel Hidalgo y Costilla, Ignacio Allende, Juan Aldama, Miguel Domínguez and more, began to plan an armed revolt against the colonial government. In 1810, the plot was discovered and Hidalgo decided to put their plans into action in September instead of the planned date in December. On 15 September, Miguel Hidalgo y Costilla declared the Grito de Dolores in the town of Dolores (Hidalgo). Hidalgo, accompanies by Ignacio Allende, left Dolores with about 800 men, half of whom were on horseback. Just through sheer numbers, Hidalgo's army had some early victories, going through the economically important and densely populated province of Guanajuato. One of Hidalgo's first stops was at the Sanctuary of Atotonilco. There, Hidalgo affixed an image of the Virgin to a lance to adopt it as his banner. He then inscribed the following slogans to his troops’ flags: "Long live religion! Long live our most Holy Mother of Guadalupe! Long live Ferdinand VII! Long live America and death to bad government!" The extent and the intensity of the movement took viceregal authorities by surprise. San Miguel and Celaya were captured with little resistance. On 21 September 1810, Hidalgo was proclaimed general and supreme commander after arriving to Celaya. At this point, Hidalgo's army numbered about 50,000. However, because of the lack of military discipline, the insurgents soon fell into robbing, looting and ransacking the towns they were capturing. On 28 September 1810, Hidalgo arrived to the city of Guanajuato. The town's Spanish and Criollo populations took refuge in the heavily fortified Alhóndiga de Granaditas granary defended
