Luis Laso de la Vega (or Luis Lasso de la Vega) was a 17th-century Mexican priest and lawyer. He is known chiefly as the author of the Huei tlamahuiçoltica ("The Great Happening"), an account published in 1649[1] which contains a narrative describing the reported apparition of the Virgin Mary before Saint Juan Diego in 1531, some 117 years earlier. The account describes the appearance of the apparition now known as Our Lady of Guadalupe to Juan Diego (an indigenous convert to Roman Catholicism, whose original pre-conversion name is given as Cuauhtlatoatzin) at the hill of Tepeyac.The book was written in the Nahuatl language.[2]