Jesolo (Lat. Equilus) is a beach resort north of the Venetian lagoon, in an area which was lagoon in the early Middle Ages.
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.
The list of lagoon settlements before the year 1000, from the “Istoria Veneticorum” by John the Deacon.
Translation of the parts related to Venice of the “De Administrando Imperio” (c.950) by Constantine VII Porphyrogenitus.