Monarchs like himself were the necessary substitute for the dominion which the conquering State had been strong enough to spurn; and he threw himself zealously into the task of forwarding the designs of Rome in the dynastic struggles of the neighbouring nations. He helped to restore Ariarathes the Fifth to his kingdom of Cappadocia,[497] and appealed to Rome against the aggressions of Prusias the Second of Bithynia. He was saved by the decisive intervention of the senate, but not until he had been twice driven within the walls of his capital by his victorious enemy.[498] His own peace and the interests of Rome were now secured by his support of Nicomedes, the son of Prusias, who had won the favour of the Romans and was placed on the throne of his father. He had even interfered in the succession to the kingdom of the Seleucidae, when the Romans thought fit to support the pretensions of Alexander Balas to the throne of Syria.[499] Lastly he had sent assistance to the Roman armies in the conflict which ended in the final reduction of Greece.[500] There was no question of his abandoning his regency during his life-time. Rome could not have found a better instrument, and it was perhaps in obedience to the wishes of the senate, and certainly in accordance with their will, that he held the supreme power until his reign of twenty-one years was closed by his death.[501] Possibly the qualities of the rightful heir may not have inspired confidence, for a strong as well as a faithful friend was needed on the throne of Pergamon. The new ruler, Attalus the Third, threatened only the danger that springs from weakness; but, had not his rule been ended by an early death, it is possible that Roman intervention might have been called in to save the monarchy from the despair of his subjects, to hand it over to some more worthy vassal, or, in default of a suitable ruler, to reduce it to the form of a province. The restraint under which Attalus had lived during his uncle's guardianship, had given him the sense of impotence that issues in bitterness of temper and reckless suspicion. The suspicion became a mania when the death of his mother and his consort created a void in his life which he persisted in believing to be due to the criminal agency of man. Relatives and friends were now the immediate victims of his disordered mind,[502] and the carnival of slaughter was followed by an apathetic indifference to the things of the outer world. Dooming himself to a sordid seclusion, the king solaced his gloomy leisure with pursuits that had perhaps become habitual during his early detachment from affairs. He passed his time in ornamental gardening, modelling in wax, casting in bronze and working in metal.[503] His last great object in life was to raise a stately tomb to his mother Stratonice. It was while he was engaged in this pious task that exposure to the sun engendered an illness which caused his death.