The sack of Antwerp, often known as the Spanish Fury at Antwerp, was an episode of the Eighty Years' War. It is the greatest massacre in the history of the Low Countries.
Anonymous contemporary depiction of the "Spanish Fury" in Antwerp (Museum Aan de Stroom)
A tercio, Spanish for "[a] third") was a military unit of the Spanish Army during the reign of the Catholic Monarchs of Spain and Habsburg Spain in the early modern period. They were the elite military units of the Spanish monarchy and the essential pieces of the powerful land forces of the Spanish Empire, sometimes also fighting with the navy.
Surrender of Breda, by Velázquez, shows Ambrosio Spinola (at right), commander of a Spanish tercio, receiving the keys to the city from a defeated Dutch general in 1625.