centre of the exarchate, and the most senior military officials of the Empire, were situated in Ravenna. The subordinate military officials who were their representatives in the Venetian lagoons were called tribunes, and only in about AD 697 were the lagoons made a separate military command under a (). Notwithstanding the election of the first , vassalic evidence such as honours and orders received by the doge from the Emperor implies that Venice was considered part of the Byzantine Empire even after the capture of Ravenna by the Lombards. Despite the (803), which recognised Venice as Byzantine territory, the influence of the Eastern Roman Emperor slowly faded away. By 814 Venice functioned as a fully independent republic. Even so, Venice became a partner of the Empire and trading privileges were granted to it by the Emperors via treaties, such as the Byzantine–Venetian Treaty of 1082. The Fourth Crusade (1202–1204) was initially intended to invade Muslim-controlled areas; instead, the Crusaders attacked the capital of the Byzantine Empire, Constantinople, resulting in the temporary dissolution of the empire and the sack of its capital. As Venice was one of the participants in the Crusade its relations with the Byzantine Empire were strained during this period. Moreover, by styling themselves "Lord of one-quarter and one-eighth of the whole Empire of Romania" after the Crusade, the Doges of Venice contributed to the deterioration of the relations between the two states. Efforts to improve relations, for example through the Nicaean–Venetian Treaty of 1219, proved unsuccessful. A period of friendly relations only followed the Sicilian Vespers in 1282, when Venice, foreseeing the fall of Charles, the French King of Sicily, began forming closer relations with Byzantium. Venice had been bound by an alliance with Charles against Byzantium in 1281. Appellation The Islands were referred to, both individually and collectively, by various names. After Venice captured Cephalonia on 24 December 1500, the administration of the defense of all the islands was delegated to an official seated in Corfu. This official was being referred to as "the General of the Three Islands" () and resided at the fortress of Angelokastro from 1387 to the end of the 16th century. The Three Islands refer to Corfu, Zante and Cephalonia. The Venetian equivalent for "Ionian Islands" is , the Italian being and the Greek in Modern Greek and in . Below are the seven principal islands from north to south, including