Historical evidences suggest that history of Venice begins around 400 AD with the settlement of refugees from Roman cities such as Padua, Aquileia, Altino and Concordia (modern Portogruaro) who were fleeing successive waves of barbarian invasions. During the collapse of Roman Empire in the early years of the fifth century the barbarians swept down from northern Europe.
The invasion of Lombards in 568 has very significant place in Venice history. During the invasion parts of the east Italian cost grouped together as the exarchate of Ravenna against the Lombards. The islanders of Torcello also joined the exarchate. First time in 726, the Venetians elect their own doge which was equivalent of duke. Orso was the first Venetian doge. But in spite of all these things Byzantine officials were continued to govern the islands until the fall of the exarchate of Ravenna in 751. Eventually a treaty was signed between the Franks and the Byzantines in 814 and Venice became independent of the Carolingian empire. Byzantines got big blow in the 11th century when the Normans drived them from their last seaport and in 1082 they took he important harbour of Durrës (or Durazzo) in Albania. In return, the Byzantine emperor grants Venice an astonishing concession for help against these marauders.
Again in 12th and 13th century culmination of the great Byzantine tradition can be seen in form of Italian mosaics. Venice extended its territory from the northern tip of the Adriatic almost to Milan. The city has gotten world’s first public opera house in 1637. Eventually, losing its political will Venice found the new role which it has enjoyed ever since as a place of pleasure and delight.