High Quality Content by WIKIPEDIA articles! The Vaccaei were an ancient tribe who settled in the Meseta Central of northern Hispania. According to Diodorus Siculus, they were the most cultured group of the Celtiberians, and Silius Italicus classed them as merchants and businessmen. Their existence is proved at least from the third century BC. Polybius relates, although he wasn't an eyewitness, the capture of the Vaccean cities of Helmantica (Salamanca) and Arbucala by Hannibal in 220 BCE.