Masinissa, Or Massinissa, a king of Numidia, born about 240 B. C, died in 148. He was the son of Gala, king of the Massylians, the most powerful tribe in E. Numidia, and received a superior education at Carthage, which when he reached the age of manhood commenced its second great struggle against Rome, under the lead of Hannibal. The Carthaginians prevailed on the Massylians to declare war against Syphax, king of the Massassylians, a rival Numidian tribe, who had espoused the cause of the Romans. Masinissa commanded his father's army, routed Syphax (213), and crossed over to Spain, where the Numidian horse greatly contributed to the defeat of the brothers Cneius and Publius Scipio. Scipio Africanus the elder, by the return of Massiva, the captive nephew of the Numidian, to his uncle with presents and a courteous message, paved the way for a secret understanding with the latter, which proved disastrous to Carthage when Scipio finally carried the war into Africa. Masinissa is said to have been influenced by resentment against Hasdrubal, who had betrothed to him his daughter Sophonisba, but in order to gain over Syphax broke his promise and gave her to the latter.

Returning to Africa, where his father had in the mean while died, Masinissa reconquered his kingdom from a usurper, but was soon attacked by the Carthaginians and their new ally, was repeatedly routed, and saved his life by flight. At this juncture Scipio landed in Africa (204), and Masinissa was enabled not only to regain his possessions, but while assisting his victorious allies, jointly with Laelius, one of their commanders, took Cirta, the capital of Syphax. Sophonisba became his captive, and soon his wife. Being afraid of the influence of Has-drubal's daughter over her new consort, Scipio severely reprimanded Masinissa, and asked the surrender of the Carthaginian woman as a captive of Rome. Unable or unwilling, at the risk of his power, to defend the freedom of his wife, Masinissa saved her from the ignominy of Roman captivity by sending her a cup of poison, which she drank without hesitation. Syphax was sent to Italy, where shortly after he died. In spite of his tragic loss, Masinissa from ambition persisted in his fidelity to Rome, and his aid contributed not a little to the issue of the battle of Zama (202), in which he commanded the cavalry on the right wing of Sci-pio's army, and which terminated with the rout of Hannibal. Peace was concluded soon after (201), and Masinissa was rewarded by the victors with a part of the territories of Syphax. He reigned in peace for 50 years, developing the resources of his kingdom by the promotion of agriculture, and extending its limits by annexations from the possessions of Carthage, which were approved of by the senate of Rome, and in consequence of which a few years before his death he once more entered the field of battle, when over 90 years old.

His defeat of the Carthaginians made it easier for the Romans subsequently to conquer them; and the last Punic war commenced soon after, in the second year of which Masinissa died, leaving his possessions to be divided by Scipio among his three legitimate sons Micipsa, Gu-lussa, and Mastanabal, with rich donations to their very numerous illegitimate brothers.