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.
First Mexican Empire
After signing the Declaration of Independence of the Mexican Empire of 28 September 1821, the Mexican Congress intended to establish a commonwealth whereby the King of Spain, Ferdinand VII, would also be emperor of Mexico, and both countries would be governed by separate laws and form separate legislative bodies. If the king refused the position, the law provided for another member of the House of Bourbon to accede to the Mexican throne. However, the goal was merely a political tactic to appease the last royalists, and full independence was expected. King Ferdinand, however, refused to recognize Mexico's independence and said that Spain would not allow any other European prince to take the throne of Mexico.