During the Austro-Prussian War of 1866, Italy fought alongside Prussia in the hope of territorial gains in Venetia. Following the Prussian defeat of the Austrian army, the fighting shifted to the Adriatic when the Italian fleet was sent to escort an invasion convoy against the Island of Lissa. The Austrian fleet, under Adminral von Tegetthof, was theoretically weaker than the Italian force but whereas Count Persano was irresolute, his Austrian opponent was bold and imaginative. The resulting battle on 20 July 1866 was the first encounter between iron-clads outside American waters and the first major action between European fleets since the Napoleonic Wars. Although a decisive victory for Austria, the battle was of no lasting importance except in the tactical sense. The specatular ramming an sinking of the Re d'Italia by von Tegetthof's flagship Ferdinand Max was to influence naval architects for the rest of the centruy. Thereafter, ships were built with massive stems and the navies of the world practised ramming techniques for thirty years hoping to emulate what had happened at Lissa.