He was listed as a "language authority" in the first 18th century edition of the Official Spanish Language Dictionary[1]. In 1736, Villegas' two-volume work on Russia was published, entitled Historia de Moscovia y vida de sus zares, con una descripción de todo el imperio, su gobierno, religión, costumbres y genio de sus naturales. Madrid, Imprenta del convento de la Merced), 2 vols (1736)[2].