“When their enemies fall they cut off their heads and fasten them about the necks of their horses; and turning over to their attendants the arms of their opponents, all covered with blood, they carry them off as booty, singing a paean over them and striking up a song of victory, and these first-fruits of battle they fasten by nails upon their houses, just as men do, in certain kinds of hunting, with the heads of wild beasts they have mastered.” — Diodorus Siculus, Library of History (on the Celts)