Birth

Despite the popular legend that Venice was first established by refugees of the fallen city of Troy  (a myth similar to the founding of Rome)  most historians agree today that the original population of Venice was consisted of people from several Roman cities in the wider area fleeing the successive Germanic and Hun invasions of Italy in the 5th century during the Great Migration Period. The wider region was however already occupied by the Adriatic Veneti, people closely related with the Illyrians and the Eneti, mentioned by Homer and linked with the story of the fall of Troy and the Trojan prince Antenor, by several Roman historians.

https://en.wikipedia.org/wiki/Migration_Periodhttps://en.wikipedia.org/wiki/Veneto

After the coming of the Lombards in Italy many inhabitants of today’s Veneto chose to move southwards, seeking safety on a shallow lagoon periodically occupied by a small fishing community depending to the ebb and flow of the water up to that point in time. The area of modern day Venice, one of the few that had remained untouched by the invaders, was still under the rule of the (Eastern) Roman Empire and would be incorporated into the Exarchate of Ravenna, a group of allied Italian duchies that tried to stand against the Lombards.

https://en.wikipedia.org/wiki/Byzantine_Empire#/media/File:Byzantiumby650AD.svghttps://commons.wikimedia.org/wiki/File:Assassination_of_Alboin.jpg