Venice is divided into six sestiere whose origin is as old as the city of Venice itself. As far as we know, they have always been there.
Venice was an independent state for almost a millennium, but it might note have been. It all hinged on a single battle fought in the Venetian lagoon in 810.
Recently discovered frescoes in the church of Torcello, former seat of the bishop, attest the close connections early Venice had to the Caroligian empire.