Numidia (nōōmĬd´ēə), ancient country of NW Africa, very roughly the modern Algeria. It was part of the Carthaginian empire until Masinissa, ruler of E Numidia, allied himself (c.206 BC) with Rome in the Punic Wars. After the Roman victory over Carthage led to peace in 201 BC, Masinissa was awarded rule of all Numidia. This began Numidia's most flourishing period, culturally and politically. Numidia's encroachments on reviving Carthage furnished Rome with a pretext for the Third Punic War (149–146 BC). Masinissa's successor was Micipsa (148–118 BC), one of whose heirs, Jugurtha, brought on a fatal war with Rome. Later, in the Roman civil war, King Juba I sided with Pompey, and Numidia lost (46 BC) all independence with Julius Caesar's victory. Juba II was favored by the Romans as a subject prince, and the region subsequently flourished for several centuries. Numidia was invaded by the Vandals in the 5th cent. AD and by the Arabs in the 8th cent. The main urban centers of ancient Numidia were Cirta (now Constantine) and Hippo Regius (now Annaba).