Gaspar de Guzmán, Count-Duke of Olivares

Gaspar de Guzmán y Pimentel, 1st Duke of Sanlúcar, 3rd Count of Olivares,, known as the Count-Duke of Olivares, was a Spanish royal favourite of Philip IV and minister. He was appointed as Grandee on 10 April 1621, a day after the ending of the Twelve Years' Truce, and was a key figure that shaped state policy in Spain until January 1643. During his rule, he over-exerted Spain in foreign affairs and unsuccessfully attempted domestic reform. His policy of committing Spain to recapture Holland led to a renewal of the Eighty Years' War while Spain was also embroiled in the Thirty Years' War (1618–1648). In addition, his attempts to centralise power and increase wartime taxation led to revolts in Catalonia and in Portugal, which brought about his downfall.