Plan de Iguala

The Plan of Iguala, proclaimed by Agustín de Iturbide on February 24, 1821, rested on three guarantees: the Catholic religion as the faith of the new nation, the independence of Mexico, and the union of Europeans and Americans. The army formed to uphold them was called the Ejército Trigarante, the Army of the Three Guarantees.

The three colors of the Mexican flag — green, white, and red — are traditionally associated with those guarantees.