Diaz, Francisco a Spanish missionary, was born at S. Cebrian de Mayuelas, in old Castile. After entering the Dominican order, he was, in 1632, sent as a missionary to the Philippine Islands. In 1635 he went to China, where he labored as a missionary in several provinces. In consequence of his zeal he had often to suffer from persecution, and finally was killed by the throwing of a stone, Nov. 4,1646. He wrote a number of works in the Chinese language, the most celebrated of which is a catechism (Ky-Mung, published in 1650, and in many subsequent editions). He is also the author of a Chinese-Spanish dictionary, which contains 7160 Chinese characters. — Hoefer, Biographie Generale, 14:56.