Spanish governor of the Netherlands during one phase (1573–76) of the Dutch revolt called the Eighty Years' War. Succeeding the tyrannical Fernando Álvarez, duque de Alba (Alba, Fernando Álvarez de Toledo y Pimentel, 3er duque de (3rd duke of)), he tried unsuccessfully to compromise with the rebellious provinces.

Requesens's early career was as a government official and diplomat. In 1563 he gained King Philip II's (Philip II) confidence as his representative at Rome. In 1568 he was made lieutenant general to Don Juan de Austria during the suppression of the Morisco revolt in Granada. He also accompanied Don Juan in the Lepanto campaign, his function being to control his nominal commander in chief, whose excitable temperament was distrusted by the king. Philip then named him viceroy in Milan, where he was credited with having shown moderation, though he came into sharp collision with the archbishop Charles Borromeo (Borromeo, Saint Charles), who had him excommunicated.

Requesens arrived in Brussels on November 17, 1573, having been sent to govern the Spanish Netherlands because the king wished to pursue a more conciliatory policy after the disastrous policy of repression of the duque de Alba. Requesens urged a general pardon, the dissolution of the Council of Troubles (Troubles, Council of), and the abolition of the sales tax; he also wanted to call the States General in order to negotiate with the rebels. Philip, however, refused to yield any of the essential points in dispute between him and the rebels; and the Netherlanders themselves were scarcely in a conciliatory mood. Thus, although Requesens did publish a general pardon (June 5, 1574) and offered to exchange the sales tax for a subsidy, he ultimately fell back again on the army, with considerable success, though the frequently unpaid Spanish troops were often more inclined to mutiny and to plunder the civilian population.