Pope Severinus (†640) was elected in 638, but couldn’t take up the seat due to a conflict with Roman emperor Heraclius. He was finally recognised in 640, but died two months later.
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.