ARPI (Gr. 'Apyopor ra), ancient city, Apulia, tom. W. of the coast and 5m. N. of the modern Foggia. Legend attributes its foundation to Diomedes, and the figure of a horse on its coins shows the local importance of horse-breeding in early times. Its territory extended to the sea, and Strabo says that from the ex tent of the city walls one could gather that it had been one of the greatest cities of Italy. As a protection against the Samnites Arpi became an ally of Rome and remained faithful until after the battle of Cannae, but Fabius captured it in 213 B.C., and it never recovered its former importance.