Codex Escalada
[1] The codex Escalada bears several significant creases both lengthwise and laterally, and the edges are abraded which, together with a deep yellowish patina, impedes a clear reading of it; however, the main features can be distinguished.
This depicts the apparition which is said to have occurred on 12 December 1531 on the hill of Tepeyac located six kilometers (four miles) north of the main plaza of Mexico City.
Above the central landscape is the date "1548" beneath which are four lines of Nahuatl text written in the Latin alphabet which can be translated as: "In this year of 15[0]31 there appeared to Cuauhtlatoatzin our dearly beloved mother Our Lady of Guadalupe in Mexico".
[5] Valeriano was juez-gobernador (or judge-governor) of his home town of Azcapotzalco from 1565 to 1573, and of San Juan Tenochtitlan thereafter, and he had been a pupil and later associate of Sahagún in the compilation of an encyclopedic account of Nahua life and culture before the Spanish conquest assembled between approximately 1540 and 1585 and known most famously through the Florentine Codex.
[7] The iconography of the Virgin on the parchment is notable for the absence of three features which have been an enduring part of the image: the aureole or golden rays framing her, the crown on her head, and the angel with folded cloth at her feet.
The first and last features are still visible in the image preserved in the Basilica of Guadalupe on what is said to be Juan Diego's tilma or mantle, but the crown had disappeared by 1895, in circumstances which remain obscure.
[9] A sequence of marks on the fringe of the Virgin's mantle falling down over her left shoulder have been interpreted as stars but (as with the possible moon) are too vestigial to permit a secure identification.
Before the discovery of the parchment, the earliest documented reference to Juan Diego which has survived had been Miguel Sánchez's Imagen de la Virgen María, published in Mexico in 1648.
[12] Nevertheless, the parchment contributes no previously unknown facts relative to Juan Diego or the apparitions, for his native name and the year of his death were already known from other sources, as was the role of Valeriano in promoting the cult of Our Lady of Guadalupe (if, indeed, the Nican Mopohua is to be attributed to him, as it traditionally has been, recent tentative challenges notwithstanding).
[17] In April 2002, on the eve of the canonization of Juan Diego, the owners waived their right to anonymity and, in a public ceremony, donated the parchment to the Archbishop of Mexico, since then it has been kept in the Historical Archives of the Basilica of Guadalupe.
[20] The parchment was consigned by Escalada to a team of 18 experts of various disciplines assembled at the Centro de Física Aplicada y Tecnología Avanzada UNAM (Querétaro campus) and coordinated by Professor Victor Manuel Castaño, who subjected it to a range of non-destructive tests to determine the age, authenticity and integrity of the materials.
[21] A copy of the signature as it appears on the parchment was sent to Dr. Charles E. Dibble, a former distinguished professor of anthropology of the University of Utah and one of the leading scholars in Sahagún studies.
The results of all these analyses and investigations were published by Escalada in July 1997 as an 80-page fifth volume or appendix to his Enciclopedia Guadalupana, complete with photographs and technical data.
