The Narentines took more liberties in their raiding quests while the Venetian Navy was abroad, as when it was campaigning in Sicilian waters in 827–882. As soon as the Venetian fleet would return to the Adriatic, the Narentines temporarily abandoned their habits again, even signing a Treaty in Venice and baptising their Slavic pagan leader into Christianity. In 834 or 835 they broke the treaty and again they raided Venetian traders returning from Benevento, and all of Venice's military attempts to punish them in 839 and 840 utterly failed. Later, they raided the Venetians more often, together with the Arabs. In 846, the Narentines broke through to Venice itself and raided its lagoon city of Caorle. This caused a Byzantine military action against them that finally brought Christianity to them. After the Arab raids on the Adriatic coast circa 872 and the retreat of the Imperial Navy, the Narentines continued their raids of Venetian waters, causing new conflicts with the Italians in 887–888. The Venetians futilely continued to fight them throughout the 10th and 11th centuries.