The Battle of Comacchio in 809 was a naval battle between a Byzantine fleet dispatched from Venice and the Frankish garrison of the island of Comacchio.
A Byzantine fleet from Constantinople under its commander Paul, the governor of Cephalonia, arrived in Venice by way of Dalmatia and sent a fleet detachment to anchor at Comacchio.
They skirmished with the Franks, were defeated and retreated to Venice.
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