December 12, patronal feast of Mexico and a holy day of obligation there, commemorating the apparition of the Blessed Virgin to an Indian convert, Juan Diego, in 1531, whom she instructed to convey to the bishop her desire that a chapel be erected in her honor on the spot where she had appeared. As a sign she imprinted her image on the peasant's mantle, which is preserved in the shrine and to the intercession of which many miracles have been attributed. Pilgrimages have been made almost uninterruptedly since the apparition. The picture, which is on coarsely woven Indian cloth, is assumed to represent the Immaculate Conception, being the figure of a maiden with the sun, moon, and stars, and an angel under the crescent. Its marvelous tints and perfect proportions have puzzled many painters. Devotion to Our Lady of Guadalupe was encouraged by many popes and Benedict XIV named her patroness of Mexico. The special Mass and Offices of the feast may be said by Mexican priests on the 12th day of every month.