Under the government of Viceroy Miguel José de Azanza he fought with severity and cruelty to subdue the Indians of the area.

Calleja married Francisca de la Gándara, a very rich Criolla and owner of the hacienda of Bledos.

With the Grito de Dolores of Miguel Hidalgo on September 16, 1810, supporters of independence rose in many places in New Spain.

At Monte de las Cruces, at the gates of Mexico City, 80,000 insurgents under Hidalgo and Ignacio Allende defeated the royalists on October 30, 1810.

After the retreat of the insurgents, Viceroy Francisco Javier Venegas ordered Calleja, now a brigadier in command of a cavalry division, to march from San Luis Potosí to the aid of the capital.

On the march between Querétaro and Mexico City, Calleja met the insurgents in the plains of San Jerónimo Aculco, where he decimated them on November 7, 1810.

The insurgents were on the point of victory when a grenade ignited a munitions wagon in their camp, sowing confusion.

A remnant of the rebel forces, including Hidalgo and other leaders, began retreating toward the United States.

Calleja's 4,000 troops became the basis of the royalist Army of the Center that fought Hidalgo, Ignacio López Rayón and Father José María Morelos.

In his home in Mexico City he received royalists who were discontented with Viceroy Venegas's inability to suppress the insurrection.

Calleja was a determined, unscrupulous, cruel ruler who tolerated the numerous abuses of his commanders; he was someone to be feared.

He returned to Spain, where he was given the title of Conde de Calderón and the grand crosses of Isabel the Catholic and San Hermenegildo.