Gasparo De Guzman Olivarez, count, a Spanish statesman, born in Rome, Jan. 0, 1587, died in Toro, July 22, 1045. His father was ambassador at the papal court of Sixtus V. He studied at the university of Salamanca, and was appointed gentleman of the bedchamber to the prince of Asturias, afterward Philip IV., who in 1621 bestowed upon Olivarez the title of duke of San Lucar, and appointed him minister in place of his uncle the duke of Uceda. Olivarez dismissed some of the best servants of the state to make room for his own creatures, and curtailed government expenses only to obtain the means of gratifying his taste for pomp and splendor. He aimed at reconquering the provinces which Spain had recently lost, and restoring the kingdom to her old supremacy in Europe; but in this attempt he had to encounter the superior skill of the French minister Cardinal Richelieu. Availing himself of the expiration of the truce with Holland concluded in 1009, he reopened hostilities with the Dutch in 1021, but was unsuccessful, and the Spanish colonies were almost ruined. Meanwhile Spain had been obliged to give up the Valtellina. Olivarez, nevertheless, attempted to make her influence felt in Italy and Germany, while he fostered troubles and conspiracies in France; but in these attempts he signally failed.

The Spanish troops sent to assist the Austrians against the German Protestants were worsted at nearly every point; and finally the flame of insurrection, fanned by Richelieu's intrigues, broke out within the Spanish dominions. The province of Catalonia rebelled in 1040, and at the same time Portugal threw off the Spanish yoke. Philip's eyes were finally opened, and he dismissed Olivarez in 1043, who was supplanted by his nephew, Don Luiz de Haro. For publishing his defence he was banished to Toro.