Philip III of Spain

Born in Madrid on 14 April 1578 to Philip II and Anna of Austria — uncle and niece, as well as cousins — he became King of Spain, Portugal, Naples, and Sicily in 1598. One year later he married another Habsburg cousin, Margaret of Austria. He delegated nearly all power to the Duke of Lerma, whose influence defined the reign, while military success in the territories depended on unpredictable commanders like Ambrogio Spinola. His rule saw a temporary peace with the Dutch from 1609 to 1621 and Spain's entry into the Thirty Years' War in 1618, but economic troubles took root early. Known in Spain…