Rodrigo de Silva Mendoza y Sarmiento (Madrid; 1600 - León; 1664), was 2nd Marqués of Alanquer, 2nd Count of Salinas, and Duke-consort of Híjar, through his marriage with the 4th Duchess of Híjar, Isabel Fenández of Híjar. He plotted in 1648 to become King of Aragon and died in prison. He married in october 1622 with Isabel Fenández of Híjar, granddaughter of Ana de Mendoza, Princess of Eboli. Despite being an adversary of Olivares, he received in 1640 a military command in the War against Portugal. He had the ambition to succeed Olivares as Valido and plotted against his successor Luis de Haro.