river, Marche region, central Italy, rising in the Etruscan Apennines (Appennino Tosco-Emiliano) and flowing for 68 mi (109 km) east-northeast into the Adriatic Sea just south of Fano. The lower valley of the river (the ancient Metaurus) was the scene of a great Roman victory over the Carthaginians in 207 BC, when the consuls Marcus Livius Salinator and Claudius Nero defeated and slew Hasdrubal, the brother of the Carthaginian leader Hannibal. The battle was a decisive turning point in the Second Punic War.