Gaspar Alfonso Pérez de Guzmán, 9th Duke of Medina Sidonia

The Duke succeeded his father as Captain General of Andalucía and the Atlantic Ocean (Mar Océano).

Though both Portugal and Catalonia had strong cultural identities, an historical record of independence, and popular support, Andalusia did not, and the rebellion failed.

The duke had the support of his brother-in-law, John IV of Portugal, but the promised naval aid from France and the Netherlands did not arrive.

[1] In 1622, aged 20, he married his 14-year-old aunt Ana María de Guzmán (1607–1637), having four children by her of which only the youngest survived: In March 1640, the 9th Duke was married for a second time to Seville noblewoman Juana Fernández de Córdoba (1611-1680), daughter of the V Marquess of Priego.

They had 3 children including : In 1639, the Duke signed documents giving the considerable amount of 20,000 Ducados to his mistress Margarita Marañon Ybarra, on condition she became a nun near his palace in Sanlúcar de Barrameda, later in a Dominican convent.