Mexican War of Independence
Iturbide's assignment to the Oaxaca expedition coincided with a successful military coup in Spain against the monarchy of Ferdinand VII. The coup leaders, part of an expeditionary force assembled to suppress the independence movements in the Americas, had turned against the monarchy. They compelled the reluctant Ferdinand to reinstate the liberal Spanish Constitution of 1812 that created a constitutional monarchy. When news of the liberal charter reached Mexico, Iturbide perceived it both as a threat to the status quo and a catalyst to rouse the criollos to gain control of Mexico. Independence was achieved when conservative Royalist forces in the colonies chose to rise up against the liberal regime in Spain; it was an about-face compared to their previous opposition to the peasant insurgency. After an initial clash with Guerrero's forces, Iturbide assumed command of the royal army. At Iguala, he allied his formerly royalist force with Guerrero’s radical insurgents to discuss the renewed struggle for independence.
Mexico
On September 16, 1810, a "loyalist revolt" against the ruling junta was declared by priest Miguel Hidalgo y Costilla, in the small town of Dolores, Guanajuato. This event, known as the Cry of Dolores (Spanish: "Grito de Dolores") is commemorated each year, on September 16, as Mexico's independence day. The first insurgent group was formed by Hidalgo, the Spanish viceregal army captain Ignacio Allende, the militia captain Juan Aldama and "La Corregidora" Josefa Ortiz de Domínguez. Hidalgo and some of his soldiers were captured and executed by firing squad in Chihuahua, on July 31, 1811. Following his death, the leadership was assumed by priest José María Morelos, who occupied key southern cities.