ANDRÈS de Olmos. – Missionary in Mexico, b. in Oña (Spain) c. 1491, d. in Tampicane (Mexico) on 8 Oct. 1571. After the death of his parents he was educated in Olmos, near Valladolid, by his sister, from whom he took his surname. He then studied civil and canon law and in 1511 donned the Franciscan habit. Juan de Zumárraga, guardian of Abrojo, appointed inquisitor for the eradication of witchcraft in Cantabria, took A. as his companion in these labours and, upon being elected bishop of Mexico, brought him along (1528). In Mexico A. devoted himself to the study of indigenous languages and in a short time mastered Nahuatl, Totonac, and Huastec; he is said also to have learned Tarascan. His apostolate extended to nearly all of Mexico, though the region most evangelized was the Huasteca, in the present-day state of Tamaulipas. He founded the mission of Pánuco in 1530 and took part in the establishment of the Franciscan custodia of Tampico, erected in the same year. In 1551 he was teaching Latin at the college of Tlatelolco, opened in 1536 to train an indigenous clergy and a governing class.
He wrote several linguistic works: a grammar of Nahuatl in 1547 and a dictionary of the same language; grammars and dictionaries of Huastec and Totonac. Other works include: Libro de los siete sermones; Tratado de los pecados mortales; Tratado de los Sacramentos; Tratado de los sacrilegios in Nahuatl; a catechism and a manual of confession in Huastec. He is also the author of a sacred drama on the Last Judgment, written in Nahuatl, which was performed in Mexico with the participation of 800 Indian actors, in the presence of Viceroy Mendoza and Archbishop Zumárraga. At the request of Ramírez de Fuenleal and Father Martín de Valencia he composed a work on Mexican antiquities, the manuscript of which was lost; later he wrote a summary of this work, which Mendieta knew.