CASTILLO, DIEGO DEL (?-?). Captain Diego del Castillo led an expedition with Capt. Hernán Martín^qv from Santa Fe in 1650 to explore north central Texas by order of Gen. Hernando de Ugarte y la Concha, governor of New Mexico. Their expedition penetrated as far as the territory of the Tejas Indians, and their report of pearls on the Nueces River (the present Concho) led to the expedition of Diego de Guadalajara.^qv

BIBLIOGRAPHY: Hubert Howe Bancroft, History of Arizona and New Mexico, 1530-1888 (San Francisco: History Company, 1889; facsimile ed., Albuquerque: Horn and Wallace, 1962). Herbert Eugene Bolton, ed., Spanish Exploration in the Southwest, 1542-1706 (New York: Scribner, 1908; rpt., New York: Barnes and Noble, 1959). Charles W. Hackett, ed., Pichardo's Treatise on the Limits of Louisiana and Texas (4 vols., Austin: University of Texas Press, 1931-46).