From 12 May, 1796 to 28 December, 1797, Napoleon went through Italy on a military campaign under orders from the French government, as Napoleon would only become Emporer of the French in 1804, to send any Italian treasures found to Paris. Among the treasures taken by Napoleon were the Horses of Saint Mark and Leonardo's Paris Manuscripts, which contain the sketches of Leonardo's double hulled ship design. The Horses of Saint Mark were returned after Napoleon fell from power in 1815. On the 12 May, 1796, the Venetian Senate had already begun preparing for Napoleon's forces by creating a governor general to oversee their defences. However, all efforts to maintain neutrality in the war failed. Eventually, Venice fell and was plundered by Napoleon's forces until 28 December, 1797, when power was transitioned to a group of French police as a transition. Shortly after, on 18 January, 1798, Venice was handed over to Austria. Interestingly, in 1805, Venice was once again ceded, this time back to France, only this time, Napoleon had gained supreme power and declared himself King of Italy.

Sources:

“The Strange Vicissitudes of Leonardo's Manuscripts.” UNESCO, 3 July 2018, en.unesco.org/courier/octobre-1974/strange-vicissitudes-leonardo-s-manuscripts.

“Napoleon: Napoleon at War.” PBS, Public Broadcasting Service, www.pbs.org/empires/napoleon/n_war/campaign/page_2.html.