This painting was executed to adorn the main wall of the monumental staircase of the old building housing the Royal Pontifical University of México, which commissioned Francisco Antonio Vallejo thanks to the fame he enjoyed as the creator of numerous works for convents, churches and colleges in the capital. The work was to commemorate the special permission that Charles III, had received from Pope Clement XIV to add the invocation Mater Inmaculata (Immaculate Mother), written on the parchment held by the King, to the litany of the Virgin. Historically speaking, the worship of the Immaculate Virgin is linked to "The Royal and Distinguished Spanish Order of Charles III”, of which She was the patroness. This work, considered one of the greatest achievements of XVIIIth century painting, presents a highly theatrical scene which is reinforced by imposing classical architectural structures in the background. The Virgin is in the center, constituting a clear vertical dividing line between political power, embodied by Charles III on the right, and ecclesiastical power, embodied by Pope Clement XIV on the left. The work is heavily charged with symbols, bringing together personages from different regions and epochs in the same space. On one side we see the King of Spain and the Pontiff, taken respectively from works by the painter Antón Raphael Mengs and the engraver, Francisco Vaden, while, on the other side, there are many saints whose presence has bearing on the scene. At the feet of the Immaculate Virgin are Saint Catherine and Saint Paul, while, on Her right and left, are Saint Bernard and Saint Ildefonso, and Saint Anselm and Saint Peter Canisius, four of the Marian doctors. To the far right we can see Saint Aloysius Gonzaga, the patrón saint of students, beneath a sheaf of white lilies alluding to the purity of his life, while, on the far left, the figures of Saint John Nepomucene and Saint Thomas Aquinas, both patron saints related to students, are worthy of note. K In the section devoted to earthly affairs we can see what are probably faithful portraits of the Archbishop, Don Francisco Antonio Lorenzana, and the Viceroy, Don Antonio María de Bucareli, kneeling behind the Pope and the King as their respective representatives in New Spain. Saint Bonaventure, one of the great defenders of Marian dogma, serves as the link between the heavenly and the earthly characters. In the background there are groups of students dressed according to the institutions in which they were enrolled. This work entered the MUNAL in the year 2000.