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.
Mexican War of Independence
Iturbide's army was joined by rebel forces from all over Mexico. When the rebels' victory became certain, the Viceroy resigned. On August 24, 1821, representatives of the Spanish crown and Iturbide signed the Treaty of Córdoba, which recognized Mexican independence under the Plan of Iguala.