The Battle of Sluis was a naval battle during the Eighty Years' War in which a Dutch fleet defeated a Spanish squadron led by the Portuguese captain Federico Spinola. Though the Spanish outnumbered the Dutch, they were defeated after a lenghty and harsh battle. The Spanish commander died. Combatants Dutch rebels Spanish Empire The Eighty Years War, or Dutch Revolt (1566–1648), was the revolt of the Seventeen Provinces in the Netherlands against the Spanish king. ...