NUEVA ESTREMADURA. Nueva Estremadura (Nueva Extremadura), another name for Coahuila, was known as early as 1602, when three priests from Zacatecas were assigned to a Saltillo convent. They traveled twenty-five leagues inland, to a valley abundantly supplied with water. After seeing the pastures and realizing the possibility for the raising of sheep for wool, the priests gave it the name of Nueva Estremadura, for that western region of Spain that borders Portugal. The new province was north of the New Kingdom of León, east of Nueva Vizcaya (Chihuahua), and west of the Río Bravo (Rio Grande). Through the center of the province ran the Río de los Conchos. A map in Henderson K. Yoakum's History of Texas shows Coquila (Coahuila) or Nueva Estremadura lying below the Medina River and the New Philippines (Texas).
I. J. Cox, "The Southwest Boundary of Texas," Quarterly of the Texas State Historical Association 6 (October 1902). Charles W. Hackett, ed., Pichardo's Treatise on the Limits of Louisiana and Texas (4 vols., Austin: University of Texas Press, 1931–46).