Gil de Castejón. Alphabetum juridicvm, canonicum, civile, theoricum, practicum, morale, atque, politicum. Matriti: ex Typographia Regia, apud Ioannem Garcia Infancon, 1678. 34 cm.
Gil Fadrique de Castejón was born and baptized in Ágreda, into a family descended from the Marqués del Socorro. He was himself a knight of the order of Alcantara and held several titles. Castejón studied law at the University of Salamanca, and was admitted to the college of St. Bartolomew in November 1640. Castejón served as Associate Judge in Chancery of Valladolid before joining the Court of Philip IV as a member of the Consejo y Camara de Indias and the Consejo of Castile. He produced this authoritative two-volume dictionary on Spanish Law while serving in the court.
Written mostly in Latin, with a few notes in Spanish, the work seldom provides extensive definitions, but rather directs the reader to classical authors, European and Spanish canonists, or to the writings of contemporary Spanish jurists.
José Luis Santalo R. de Viguri. "El primer Marqués del Socorro y su descendencia." Revista Hidalguía 70 (1965): 369-433, 389.
José de Rezabal y Ugarte. "Castejón." Biblioteca de los escritores que han sido individuos de los seis colegios mayores. Madrida: En la Impr. de Sancha, 1805, pp. 59-60.