Given their strategic location, the Serra de São Mamede and Spain's Sierra de San Pedro – in particular the dominant escarpments of Marvão on the northernmost tip and Alburquerque on the southernmost tip - are likely to have played a role in conflicts between Celtiberians and Romans. While Marvão lies north of the territories of Carthaginian Iberia – which by 218 BCE reached across Southern Iberia up to the river Guadiana, the area is likely to have been crossed during the 230s and 220–218 BCE during Carthaginian slave-raiding and mercenary-recruitment campaigns focused on the Tagus valley (e.g. Hamilcar Barca's Tagus encampment at Cartaxo) and along what later became Ruta de la Plata: Iberian manpower was to play a role in the Punic Wars.