The Halberd was a type of pole arm wielded by soldiers in Europe during the Middle Ages and during The Crusades. Dante Alighieri was seen wielding the generic weapon in Acre, but discarded it in favor of Death's Scythe.
Prior to the prisoner riot in Acre, the halberd was originally hanging on a wall. However, Dante was shown taking the weapon down and wielded it adeptly during the raid. Later, after being stabbed by an assassin, Dante used the weapon against Death before stealing his Scythe and turning it against him. The Halberd was a meaningless weapon and was quickly discarded in favor of the stolen weapon.