The lagoon was settled in Antiquity, and in the 600s, there were numerous known towns, and several important cities. Venice, however, was not one of them.
Following the Lombard invasion and conquest of Venetia, a part of the Venetian population of the mainland cities fled or left for the settlements in the nearby lagoons.
The Lombard invasion of Byzantine Italy in 568 was a pivotal event in Venetian history, as it kicked off the movement towards a distinct Venetian society, culture and, ultimately, state.