Marquesses of Guevara Marqueses de Guevara Records #2 Holders Family filter On/Off 6 Diego Ventura de Guzmán y Fernández de Córdova, 14th count of Oñate * 1738 Diego Vélez de Guevara, marquess of Guevara, count of Oñate, de Villamediana y de Campo-Real Corrections and Updates To suggest a correction or an update. Click Here