At the Battle of Cannae, 2 August, 216 B.C., Carthaginian general Hannibal Barca administered one of Rome's most crushing military defeats. Depending upon the ancient source, Roman losses on the Apulian battlefield numbered anywhere from roughly 50,000, as Livy relates, to around 70,000, as Polybius insists. Hannibal had enacted a double envelopment of the Roman army, a maneuver widely considered to be a tactical masterpiece that is to this day studied in war colleges around the world.