Who settled in the Venetian lagoon after the fall of the Western Roman Empire?

Following the fall of the Western Roman Empire, the Venetian lagoon was settled by mainlanders fleeing the incursions of Lombard hordes, which began in 568 CE. These refugees sought safety on the islands of the lagoon, which were previously inhabited only by itinerant fishermen and salt workers.1

By the early 7th century, these migrations significantly increased the population of existing fishing communities located on the higher mudflats and sandbanks. Among these settlements, the Rialto group of islands eventually emerged as the central hub, becoming the heart of the city and the seat of government.21