A Nahua healer's 1552 herbal was sent to Spain, passed through a royal pharmacist and a cardinal to the Vatican, and a pope returned it to Mexico in 1990

In 1552, at the Franciscan College of Santa Cruz in Tlatelolco, the Nahua healer Martín de la Cruz wrote a book of Mexican medicinal plants in Nahuatl. His classmate Juan Badiano translated it into Latin. Friar Jacobo de Grado had it made for Don Francisco de Mendoza, who sent it to Spain, where it entered the royal library. It is the earliest known text on medical practice from the Americas. In the early 17th century it belonged to Diego de Cortavila y Sanabria, pharmacist to King Philip IV. It later passed to Cardinal Francesco Barberini. In 1902 the Barberini library became part of the Vatican Library, and the herbal went with it. It stayed in Rome for 88 more years. In 1990, after Mexico and the Vatican restored diplomatic relations, Pope John Paul II returned it to Mexico. It is held by the National Library of Anthropology and History (INAH) in Mexico City. Brito Guadarrama of the library told Excélsior it is the most important treatise on prehispanic medicine in existence. INAH published a digital edition in 2021 and a printed one in 2023.