Bernardino de Sahagún (1499-1590) was a Franciscan missionary to the Aztec (Náhua) people of Mexico.

Unlike most missionaries of the period, he researched Náhua culture and Náhuatl linguistics and compiled an unparalleled work in Spanish and Náhuatl. Leon Portilla claims for Sahagun the title of "the first anthropologist", because his methods were ahead of his times.

He assembled three groups of Náhualt "tlatimines" or wise men, from different cities. He would ask questions, compare the answers of the three independent groups, and ask more questions to clarify the differences. All this was done in Náhuatl.

Sahagun's work is known via a manuscript called the Florentine Codex . After being questioned by the Spanish authorities, he wrote a Spanish version The General History of the Things of New Spain,. Even this was too much, however, and his work was confiscated. Fortunately he had a copy, since the original was lost.

Only recently the Náhuatl part had been completely translated.