For nearly 250 years, Berber kings of the 'House of Masinissa' ruled in Numidia, which included much of Tunisia, and later in adjacent regions, first as sovereigns allied with Rome and then eventually as Roman clients. This period commenced with the defeat of Carthage by the Roman Army, assisted by Berber cavalry led by Masinissa at the Battle of Zama in 202, and it lasted until the year 40, during the reign of the Roman Emperor Gaius, also known as Caligula (37–41).