FERNANDEZ DE CORDOVA, Diego, marquis of Guadalcazar and count of Posadas, viceroy of Mexico and Peru, born in the last quarter of the 16th century (place unknown); died in Guadalcazar about 1650. He was a descendant of Gonzalo de Cordova, and was educated for a military career. In his youth he fought valiantly in the wars of Flanders, and in 1612 was appointed viceroy of Mexico. During his administration in 1613, the engineer Adrian Boot began the works for the drainage of the valley of Mexico, in 1614 the City of Lerma was founded, and in 1616 the Tepehuan Indians revolted, killing their missionaries, but Fernandez soon conquered them. During 1614 there were rumors of the approach of a Dutch fleet in the Pacific, and Fernandez fortified the port of Acapulco. He also equipped three warships there, which, after the fears of war had been dispelled, he sent in March 1615, on an exploring expedition to the coast of California. In 1620 the aqueduct of the City of Mexico was finished, consisting of 900 arches and costing 250,000f.

In 1621, shortly before the death of Philip III., Fernandez was appointed viceroy of Peru, but the sickness and death of his wife detained him for some time, and he did not reach Lima till 25 July 1622. In 1623, when the war between Spain and Holland was renewed and there was danger of an invasion by a Dutch fleet, the viceroy ordered all-important points to be fortified with the greatest activity, and gave a military organization to all the inhabitants of the coast. Fernandez remained personally for four months in Callao, and put everything in good state of defense. Early in 1624 the Dutch fleet, consisting of eleven vessels with 294 guns and 1,600 troops, under command of Admiral Jacob Clerk, appeared before Callao, and anchored at the Island of San Lorenzo. The Dutch admiral sent a fire ship against the boom and chain at the entrance of the harbor, but an unfavorable wind took it to the beach at some distance from the town, where it exploded without doing great damage. Repeated attacks and bombardments of the port were successfully repulsed by the forts and two men-of-war, the " Loreto" and" San Bartolome," anchored in the bay.

Admiral Clerk sent several expeditions against other points of the coast without notable results, and died on board his fleet. His successor, after five months of fruitless hostilities, abandoned the coast and returned to Europe. During the rest of the year Fernandez applied himself to the improvement of his government, founded the monastery of Santa Catalina in Lima, and ordered barracks to be built at Callao for the lodging of Negro slaves arriving from Africa, who had previously been kept by their importers in open camps till their sale. In 1625 he appointed his nephew, Luis de Cordova y Aree, governor of Chili, and when, in 1626, the order arrived from Madrid to take up again the warfare against the Araucanians, Fernandez sent re-enforcements and ammunitions to Chili from Callao.

In 1625, Fernandez also succeeded in quelling the civil warfare between the rival factions of the Biscavans and Vicunas in Potosi, which had lasted for three years, and on 19 October of the same year the new cathedral at Lima, which had been finished by the viceroy, was consecrated. Fernandez also hastened during his administration the construction of the cathedrals of Cuzco, Arequipa, and Guamanga. In 1626 he established the University of San Pedro Nolasco, and in the same year regulated the mail service. He had the bridge over the Apurimae River established at the most convenient point, constructed another at Chancay, and also ordered a yearly visit by one of the supreme judges through the court district to remedy the abuses committed by the judges, priests, and Spaniards generally against the Indians. Fernandez collected all official letters, information, orders, and consultations during his administration in Mexico and Peru from 1612 till 1628 in three volumes, and sent them to the council of the Indies, besides the official information given to his successors. On 14 January 1629, the new viceroy arrived, and Fernandez delivered to him the government and returned to Spain, where he resided in a palace, which he had built in the town of Guadaleazar, near Cordova.