LEON, Alonso de (lay-one'), Spanish explorer, born in Mexico about 1640; died in Cadereita early in the 18th century. He was governor of Coahuila, and in several expeditions explored the interior of New Leon. Toward the end of 1688 the Count of Galve, on assuming the government of New Spain, was informed that some French adventurers had formed establishments on the coast of Texas, and he ordered Leon to go with an expedition, accompanied by a geographer and interpreter, to that, coast. Accordingly the latter set out in the beginning of 1689, and after a long march through the desert arrived at the Bay of San Bernardo, or Espiritu Santo, where he found a partly constructed fort, but no signs of the French settlers. Hearing from friendly Indians that five of them were with a neighboring tribe in search of workmen, Leon sent a detachment to capture them, and after several days the force returned with two of the French adventurers, Jacques Grollet and Jean L'Archeveque, the others having fled. He established a garrison, or presidio, and returned to Monctova, the capital of Coahuila, despatching the two Frenchmen to Mexico, whence the viceroy sent them to Spain, recommending measures to secure the coast against the French. A royal order came to establish more presidios and missions in Texas, and Leon was sent in 1691 for this purpose; but he so oppressed the Indians that there was a general rising in 1693, and nearly all the missions were destroyed. Leon was now recalled and retired to New Leon, where he founded the town of Cadereita, and died there. His report "Relacion de mi viaje a la bahia de San Bernardo, dirigida al Exmo. Sr. virey de N. E., Conde de Galve" (1689), is kept in manuscript in the archives of the council of the Indies. Besides this there are in manuscript in the library of the University of Mexico "Diarios de Alonso de Leon" (1689) and "Relacion y Discursos del descubrimiento, poblacion y pacificacion del Nuevo Reino de Leon, temperamento y calidad de la tierra, dirigidos For Alonso de Leon al Illmo. St. Du Juan de Manosca, Inquisidor del Santo Oficio de la N. E. ano de 1690."