It was besieged by Scipio Aemilianus Africanus in the Third Punic War when the city was defeated and destroyed in 146BC. The Byrsa citadel was the seat of the proconsul of Africa within the Roman Empire. In AD439, Geiseric took possession of Carthage. The Vandal kings ruled North Africa from the Byrsa until the Byzantine emperor Justinian reconquered the province in 533.