The Venetian galley fleet under Angelo Trevisan is moored on the river Po, waiting for the right moment to attack Ferrara, a short distance away.
The Slavonian and Albanian mercenaries (called Stratioti) meanwhile make daily incursions into the Dukedom, sowing death and terror.
On the night of December 21-22, given the high level reached by the waters of the Po, bringing the enemy galleys up to the level of the embankment, the Ferrarese forces set up their famous artillery along the river and at dawn open fire.
Many ships are sunk and others captured in the chaos that follows this surprise action.
The soldiers and sailors who try to escape into the water are taken prisoner and shot or killed without mercy as soon as they reach firm ground.
It is rather a massacre than a battle.
The troops of Ferrara conquer fifteen galleys and a number of other ships.
The Venetians have lost two thousand killed or drowned and sixty flags.
Angelo Trevisan succeeds in fleeing, but his damaged galley sinks five kilometers further down river.
He will be tried in Venice for "misconduct and carelessness".
Francesco Guicciardini credits the decisive victory to Alfonso himself.
