Army of the Three Guarantees enters Mexico City; Declaration of Independence of the Mexican Empire

Background. The Mexican War of Independence concluded in 1821 after a military stalemate. Former royalist commander Agustín de Iturbide allied with insurgent leader Vicente Guerrero under the Plan of Iguala. This alliance formed the Army of the Three Guarantees, which defeated remaining Spanish forces, leading to the Treaty of Córdoba and the subsequent entry into the capital.

Entry into Mexico City. On 27 September 1821, the Army of the Three Guarantees triumphantly entered Mexico City. This event marked the end of the armed conflict and the collapse of royal government in New Spain. The entry was celebrated as a victory for independence, with the army marching in triumph under Iturbide's leadership.

Declaration of Independence. The Declaration of Independence of the Mexican Empire was drafted on 28 September 1821 in the National Palace. It was issued by the Sovereign Junta assembled in the capital. This document formally proclaimed Mexico's independence from Spain, establishing the Mexican Empire as the successor to New Spain.