In Mexico, the winter solstice festival was one of the most important celebrations of the year and it was on December 12 according to the Julian calendar used by the Spaniards until 1582. According to the Aztec calendar, Tonantzin Guadalupe (the beloved mother of the gods) was celebrated on the winter solstice, and she is still celebrated today on December 12; while their most important deity, the sun god Huitzilopochtli, was born during the month of December (panquetzaliztli). The parallel in time between this native celebration and the birth of Christ lent itself to an almost seamless merging of the two holidays. Seeing the opportunity to proselytize, Spanish missionaries brought the custom of the re-invented religious pageant to Mexico, where they used it to teach the story of Jesus’ birth to Mexico’s people. In 1586, Friar Diego de Soria obtained a papal bull from Pope Sixtus V, stating that a Christmas Mass (misa de Aguinaldo), be observed as novenas on the nine days preceding Christmas Day throughout Mexico.