The Florentine Codex is a 16th-century ethnographic research study in Mesoamerica by the Spanish Franciscan friar Bernardino de Sahagún. Sahagún originally titled it: La Historia General de las Cosas de Nueva España (in English: The Universal History of the Things of New Spain). After a translation mistake, it was given the name Historia general de las Cosas de Nueva España. The best-preserved manuscript is commonly referred to as the Florentine Codex, as the codex is held in the Laurentian Library of Florence, Italy. In partnership with Nahua men who were formerly his students at the Colegio de Santa Cruz de Tlatelolco, Sahagún conducted research, organized evidence, wrote and edited his findings. He worked on this project from 1545 up until his death in 1590. The work consists of 2,400 pages organized into twelve books; more than 2,000 illustrations drawn by native artists provide vivid images of this era. It documents the culture, religious cosmology (worldview) and ritual practices, society, economics, and natural history of the Aztec people. It has been described as "one of the most remarkable accounts of a non-Western culture ever composed." In 2002, Charles E. Dibble and Arthur J. O. Anderson were the first to translate the Codex from Nahuatl to English, in a project that took 30 years to complete. In 2012, high-resolution scans of all volumes of the Florentine Codex, in Nahuatl and Spanish, with illustrations, were added to the World Digital Library. In 2015, Sahagún's work was declared a World Heritage by the UNESCO. In 1575 the Council of the Indies suggested to the Spanish Crown to educate the native Americans in Spanish instead of using the indigenous languages; for this reason, the Spanish authorities required to Fray Sahagún to hand over all of his documents about the Aztec culture and the results of his research in order to get further details about this matter. In the meantime, the Bishop of Sigüenza, Diego de Espinosa, who was also the Inquisitor General and President of the Royal Council of Castile instructed the cleric Luis Sánchez a report about the situation of the native Americans.