But the cause of independence was not dead even if its achievement was to be entrusted to other hands.

Eager to emulate the example of their brethren in South America, small parties of Spaniards and Creoles fought to overturn the despotic rule of Ferdinand VII, only to encounter defeat from the royalists.

Then came the Revolution of 1820 in the mother country.
Forthwith demands were heard for a recognition of the liberal regime.
Fearful of being displaced from power, the viceroy with the support of the clergy and aristocracy ordered Agustin de Iturbide, a Creole officer who had been an active royalist, to quell an insurrection in the southern part of the country.
The choice of this soldier was unfortunate.

Personally ambitious and cherishing in secret the thought of independence, Iturbide, faithless to his trust, entered into negotiations with the insurgents which culminated February 24, 1821, in what was called the "Plan of Iguala." It contained three main provisions, or "guarantees," as they were termed: the maintenance of the Catholic religion to the exclusion of all others; the establishment of a constitutional monarchy separate from Spain and ruled by Ferdinand himself, or, if he declined the honor, by some other European prince; and the union of Mexicans and Spaniards without distinction of caste or privilege.

A temporary government also, in the form of a junta presided over by the viceroy, was to be created; and provision was made for the organization of an "Army of the Three Guarantees." Despite opposition from the royalists, the plan won increasing favor.
Powerless to thwart it and inclined besides to a policy of conciliation, the new viceroy, Juan O'Donoju, agreed to ratify it on condition--in obedience to a suggestion from Iturbide--that the parties concerned should be at liberty, if they desired, to choose any one as emperor, whether he were of a reigning family or not.