Plots were widespread, but it was the conspirators of Querétaro, San Miguel, and Dolores who, when they were discovered, first took up arms. The morning of Sunday, September 16, 1810, the cleric and teacher Miguel Hidalgo y Costilla, an old man who was well-to-do, influential, and brilliant, had studied with the Jesuits, and was priest of the village of Dolores, freed the prisoners and locked up the Spanish authorities. Calling his parishioners to mass, he urged them from the portal of his church to join a “cause” dedicated to the overthrow of bad government. This exhortation is officially known as the “Grito de Dolores” and is considered the high point in Mexican history.

Hidalgo left his parish with 600 followers but within a few days they had swelled to about 100,000 men—both Creole and darker skinned—from mines, haciendas, and obrajes. Although this multitude seemed to be more a mass demonstration armed with shovels and slings than an army, it encountered no resistance in San Miguel, Celaya, and Salamanca. The important mining city, Guanajuato, fell after a bloody battle and was pillaged.

The Bishop of Michoacán excommunicated Hidalgo, but the latter led his “army” against the Michoacán capital and forced the cathedral council to lift his excommunication. After Valladolid, he set out for Mexico City, which was relatively unprotected. He won the battle of Monte de las Cruces, requested a parley with the viceroy and then, without waiting for a reply, ordered a retreat during which he was defeated in San Jerónimo Aculco by the Spanish General Félix María Calleja.

The Mexican Revolution, like any historical event, varied with the passage of time and was complex in its organization and development. It arose as a clearly political protest against the Porfirian regime; but those who participated in it left the imprint of their ideas, interests, and aspirations.

In 1910 Porfirio Díaz had himself reelected president of Mexico for the sixth consecutive time. Over thirty years of a power that steadily increased but did little to renew its men and methods had resulted in the paradox of an undeniably strong present and, at the same time, an imminent weakness. Although nothing and no one appeared to be capable of discussing the Porfiriato, still less of replacing it, it was already threatened by its manifest ageing and by the ever closer possibility of the death of the caudillo. At the time of what was to be his last reelection, General Díaz was eighty years old. For all these reasons, since 1904 Mexico had been faced with the problem of who would replace the president. By lengthening his presidential term from four to six years, Díaz put off the problem, but he did not eliminate it.