Following the Conquest in 1519–1521, the Marian cult was brought to the Americas and Franciscan monks often leveraged syncretism with existing religious beliefs as an instrument for evangelization. What is purported by some to be the earliest mention of the miraculous apparition of the Virgin is a page of parchment, the "Codex Escalada", which was discovered in 1995 and, according to investigative analysis, dates from the sixteenth century. This document bears two pictorial representations of Juan Diego and the apparition, several inscriptions in Nahuatl referring to Juan Diego by his Aztec name, and the date of his death: 1548, as well as the year that the then named Virgin Mary appeared: 1531. It also contains the glyph of Antonio Valeriano; and finally, the signature of Fray Bernardino de Sahagun that was authenticated by experts from the Banco de Mexico and Charles E. Dibble.