His singular skill in devising fresh taxes to meet the enormous demands of Napoleon's government made him the most-hated man in Lombardy.
The Senate assembled on 19 April and Prina's party suggested that delegates should be despatched to Vienna to request that Eugene Beauharnais be raised to the throne of a free Italian kingdom.
Not finding him there, the rioters rushed to his house, which they wrecked, and seized the doomed minister, who was discovered in a remote chamber donning a disguise.
Over the course of four hours, the angry rioters dragged him about the town, until wounded, mutilated, almost torn to pieces, Prina received his death blow.
The authorities were passive, and although some courageous persons actually rescued the victim at an early stage and concealed him in a friendly house, the mob soon discovered his refuge and were about to force an entrance, when the dying man surrendered to save his saviours' property.