Mexican War of Independence
The Mexican War of Independence () was an armed conflict, and the culmination of a political and social process which ended the rule of Spain in 1821 in the territory of New Spain. The war had its antecedent in Napoleon's French invasion of Spain in 1808; it extended from the Cry of Dolores by Father Miguel Hidalgo y Costilla on September 16, 1810, to the entrance of the Army of the Three Guarantees led by Agustín de Iturbide to Mexico City on September 27, 1821. September 16 is celebrated as Mexican Independence Day.
Treaty of Córdoba
On September 27, 1821, the Army of the Three Guarantees entered triumphantly into Mexico City and on the following day, the Declaration of Independence of the Mexican Empire was widely known. The Spanish Cortes refused to accept the validity of the Plan of Iguala or the Treaty of Córdoba. Spain did not recognize Mexico's independence until December 1836. Therefore, the Mexican Congress elected a Mexican monarch the following year. Iturbide was proclaimed emperor of Mexico on May 18, 1822. The monarchy lasted three years, and after the republican revolution of Casa Mata, the Congress no longer considered the Plan of Iguala or Treaty of Córdoba in effect.