The Battle of Piave River was fought on 8 May 1809 between the Franco-Italian army under the command of Eugène de Beauharnais and an Austrian army led by Archduke John of Austria. The Austrian commander made a stand behind the Piave River but he suffered a defeat at the hands of his numerically superior foes. The combat took place near Nervesa della Battaglia, Italy during the War of the Fifth Coalition, part of the Napoleonic Wars.

Eugène Rose de Beauharnais was a French nobleman, statesman, and military commander who served during the French Revolutionary Wars and the Napoleonic Wars. Through the second marriage of his mother, Joséphine de Beauharnais, he was the stepson of Napoleon Bonaparte. Under the French Empire he also became Napoleon's adopted son. He was Viceroy of the Kingdom of Italy under his stepfather, from 1805 to 1814, and commanded the Army of Italy during the Napoleonic Wars. Historians consider him one of Napoleon's most able relatives.