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.
Mexican War of Independence
In the early 19th century, Napoleon's occupation of Spain led to an outbreak of numerous revolts against colonial government across Spanish America. After the abortive Conspiracy of the Machetes in 1799, a massive revolt in the Bajío region was led by secular cleric Miguel Hidalgo y Costilla. His Grito de Dolores was the first stage of the insurgency for Mexican independence. Before 1810, there was no significant support for independence. Once the Hidalgo revolt was underway, it received major support only in the Bajío and parts of Jalisco.