The First Ottoman–Venetian War was fought between the Republic of Venice with its allies and the Ottoman Empire from 1463 to 1479. Fought shortly after the capture of Constantinople and the remnants of the Byzantine Empire by the Ottomans, it resulted in the loss of several Venetian holdings in Albania and Greece, most importantly the island of Negroponte (Euboea), which had been a Venetian protectorate for centuries. The war also saw the rapid expansion of the Ottoman navy, which became able to challenge the Venetians and the Knights Hospitaller for supremacy in the Aegean Sea. In the closing years of the war, however, the Republic managed to recoup its losses by the de facto acquisition of the Crusader Kingdom of Cyprus.

The Triarchy of Negroponte was a crusader state established on the island of Euboea after the partition of the Byzantine Empire following the Fourth Crusade. Partitioned into three baronies run by a few interrelated Lombard families, the island soon fell under the influence of the Republic of Venice. From circa 1390, the island became a regular Venetian colony as the Realm of Negroponte.