The Battle of Mons Lactarius (also known as Battle of the Vesuvius) took place in 552 or 553 AD during the Gothic War (535–554) between Byzantine forces and the Ostrogoths (Goths) near Mount Vesuvius in Italy.
Byzantine forces, led by General Narses confronted the army of the Gothic King Teias in the rugged terrain near Mount Vesuvius. After two months of stalemate, the two sides finally engaged in open battle. Teias was killed in the fighting, marking the collapse of Gothic leadership. The remaining Gothic troops resisted for a short time but ultimately surrendered under negotiated terms. This victory ended Gothic power on the Italian peninsula, allowing the Byzantines to reestablish their authority there.