In addition to my historical research and academic publications, I am actively involved with several prestigious international institutions, historical societies, and chivalric corporations. Below is an overview of my institutional affiliations, official honours, and certified heraldic records.

Coat of arms of the Duque lineage,

nobility lineage of Mario Santos de Grajal y López.

Scholarly & Academic Appointments

• Member of the Royal Historical Society (RHS), United Kingdom.

• Member of the Europeana Network Association, Europe’s digital cultural heritage platform.

Nobiliary Corporations

• Associated Noble (Noble Asociado) of the Real Asociación de Hidalgos de España.

– Historical Proof: My lineage is proven via direct descent from my 12th grandfather, Don Francisco de Santos, Hidalgo, whose noble status was legally certified by the Royal Chancery of Valladolid in 1571 (Santos de Grajal y López, M. (2026). Proving nobility in Early Modern Castile. History and Art Journal, 1(1), Article 3).

– Official Admission: My entry record and approval are published in the official Gacetilla de Hidalgos Official Gazette (“La Asociación. Nuevos Ingresos”. Hidalgos. La Revista de la Real Asociación de Hidalgos de España. Gacetilla de Hidalgos. Invierno 2016 Año LVIII Nº 545 p.47).

– Heraldic Proof: My armorial registration and corporate coat of arms are published in the official Gacetilla de Hidalgos Armorial Record (“La Heráldica de los Asociados”. Hidalgos. La Revista de la Real Asociación de Hidalgos de España. Gacetilla de Hidalgos. Invierno 2017 Año LIX Nº 549 p. 44).

• Member of the Spanish Youth Nobility Group, CILANE (“Commission d’information et de liaison des associations nobles d’Europe”) 

• Knight of Justice (Caballero de Justicia) of the Elenco de Caballeros y Damas del Reino de España.

• Cross of Justice of the Capítulo Noble of Fernando VI