William I, Prince of Orange (1533-1584), also known as William the Silent and William the Taciturn, was a wealthy nobleman from the Dutch provinces of the Spanish Netherlands. He originally served the Spanish Habsburgs, but increasing dissatisfaction with the centralisation of power away from the local estates and Spanish persecution of Dutch Protestants led William to join the Dutch revolt and becoming its main leader.

As leader of the uprising, William led the Dutch to several successes against the Spanish, setting off the Eighty Years' War (1568-1648). He was declared an outlaw by the Spanish king in 1580, before helping to declare the formal independence of the Dutch Republic, also known as the United Provinces, in 1581. He was eventually assassinated by Balthasar Gerard in 1584.