The Uskok War, also known as the War of Gradisca, was fought by the Austrians, Croats, and Spanish on one side and the Venetians, Dutch, and English on the other. It is named for the Uskoks, soldiers from Croatia used by the Austrians for irregular warfare. Since the Uskoks were checked on land and were rarely paid their annual salary, they resorted to piracy. In addition to attacking Turkish ships, they attacked Venetian merchantmen. Although the Venetians tried to protect their shipping with escorts, watchtowers, and other protective measures, the cost became prohibitive.

The Treaty of Peace concluded through the mediation of Philip III, Holy Roman Emperor Matthias, Archduke Ferdinand of Austria and the Republic of Venice resolved that pirates would be driven from the maritime areas of the House of Austria. The Venetians returned to their Imperial and Royal Majesty all the places occupied by them in Istria and Friuli.