The events around the demise of the Exarchate of Ravenna only involved the Venetians marginally. It is nevertheless important to the history of Venice.
The Lombard invasion of Byzantine Italy in 568 was a pivotal event in Venetian history, as it kicked off the movement towards a distinct Venetian society, culture and, ultimately, state.
In late Antiquity the north-east of the Italian peninsula suffered many invasions. The wars caused people to move to the safer lagoon areas, and hence to the foundation of Venice.