Tomás Fernández de Medrano was the Secretary of State and War of the Dukes of Savoy, and a 16th and 17th century nobleman from the Medrano family in La Rioja, Spain. Tomás is the author of the political treatise "República Mista," published by Juan Flamenco in Madrid, 1602. Medrano was the divisero, alcalde and lord of Valdeosera, knight in the Order of Saint John, secretary of the Holy Chapters and Assemblies of Castile, Manager of the Grand Prior of Castilla San Juan and The Most Reverend patron and master of the convent of Saint John of Acre in the town of Salinas de Añana. He also served for 8 years in the service of Enrique de Guzmán, 2nd Count of Olivares, as well as secretary of Giovanni Andrea Doria, Marques de Torilla in 1579–1581. Medrano was married to Doña Isabel Ibañez de Sandoval, relative of the first Duke of Lerma, Francisco de Sandoval y Rojas.

Francisco Gómez de Sandoval y Rojas, 1st Duke of Lerma, 5th Marquess of Denia, 1st Count of Ampudia, was a favourite of Philip III of Spain, the first of the validos through whom the later Habsburg monarchs ruled. His administration was marked by costly wars, including the Twelve Years' Truce with the Dutch Republic, financial mismanagement, and the controversial expulsion of the Moriscos. Eventually, he was deposed in 1618 under a palace intrigue orchestrated by his son and political rival, Cristóbal de Sandoval. Lerma retired as a cardinal and was succeeded by the Count-Duke of Olivares but faced financial penalties and died in 1625 at Valladolid.