The Grito de Dolores ("Cry of Dolores"), also known as El Grito de la Independencia ("Cry of Independence"), marked the beginning of the Mexican War of Independence. The Battle of Guanajuato, the first major engagement of the insurgency, occurred four days later. After a decade of war, Mexico's independence from Spain was effectively declared in the Declaration of Independence of the Mexican Empire on 27 September 1821. Agustín de Iturbide is proclaimed Emperor of the First Mexican Empire by Congress, crowned in the Cathedral of Mexico. Unrest followed for the next several decades, as different factions fought for control of Mexico.