Mexican War of Independence recognized Mexican independence under the Plan of Iguala. On September 27, 1821 the Army of the Three Guarantees entered Mexico City, and the following day Iturbide proclaimed the independence of the Mexican Empire, as New Spain was henceforth to be called. The Treaty of Córdoba was not ratified by the Spanish Cortes. Iturbide included a special clause in the treaty that left open the possibility for a criollo monarch to be appointed by a Mexican congress if no suitable member of the European royalty would accept the Mexican crown. Half of the new government employees appointed were Iturbide's followers. On
Spanish conquest of the Aztec Empire "The Aztecs Under Spanish Rule: A History of the Indians of the Valley of Mexico, 1519–1810" (1964) were central in reshaping the historiography of the indigenous and their communities from the Spanish Conquest to the 1810 Mexican independence era. Scholars who were part of a branch of Mesoamerican ethnohistory, more recently called the New Philology have, using indigenous texts in the indigenous languages, been able to examine in considerable detail how the indigenous lived during the era of Spanish colonial rule. A major work that utilizes colonial-era indigenous texts as its main source is James Lockhart's "The Nahuas After the