Torcello was one of the first settlements in the lagoon, inhabited by people from the Roman town of Altino on the mainland, already in the late 500s or early 600s. In the early Middle Ages, Torcella was larger then Venice.
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.