Spanish attempts to reconquer Mexico
Mexican independence was officially achieved on September 27, 1821, under the Treaty of Córdoba. Spain did not recognize the treaties, arguing that the viceroy Juan O'Donojú had no authority to recognize the independence of any overseas province. This situation was dangerous to the newly acquired independent status of the nation, which had not yet been recognized by any of the European powers that could support it, and the threat of Spanish reconquest was a constant worry to the leaders of the nascent regime. On May 13, 1822 decrees were issued by the government to imprison anyone who conspired against Mexico's independence.
Timeline of Mexican War of Independence
The Mexican war of independence was an attempt, ultimately successful, led by Mexican-born Spaniards, called "criollos", to shake off the rule of Spain and the political and social dominance in Mexico of a small number of Spanish-born people living in Mexico, called "peninsulares" or derisively "gapuchines." The war began in 1810 with a small group of criollos in the Bajio region, supported by a large number of mixed-blood mestizos and indigenous people.