*The new Persian empire.* The widespread military insubordination was all the more dangerous since new and more aggressive foes began to threaten the integrity of the empire. In 227 A. D. the Parthian dynasty of the Arsacids was overthrown by the Persian Ardaschir (Artaxerxes) who founded the dynasty of the Sassanids. The establishment of this new Persian kingdom was accompanied by a revival of the national Persian religion, Zoroastrianism, and of the Persian claims to the eastern Roman provinces. In 231 the Persians drove the Roman troops out of Mesopotamia and penetrated Cappadocia and Syria. Alexander himself then went to the East, where he took the offensive in the following year. The details of his campaign are uncertain, but at any rate Mesopotamia was recovered and Alexander celebrated a triumph over the Persians in Rome (233 A. D.). *The Germanic campaign and death of Severus Alexander.* But the northern frontier was threatened by the attacks of Germanic tribes, and in 234 Alexander assumed the conduct of operations on the Rhine, with his headquarters at Mainz. The barbarians were induced to make peace, but only by the payment of subsidies, and this cost Alexander the respect of the army, who were disgruntled at his policy of retrenchment and his subservience to his mother. A mutiny broke out, led by Gaius Julius Verus Maximinus, a Thracian of peasant origin who had risen from the ranks to high command. Alexander and Julia Mamaea were put to death, and Maximinus was proclaimed Augustus (March, 235 A. D.). With his accession began a half century of confusion and anarchy. VI. THE DISSOLUTION AND RESTORATION OF THE EMPIRE: 235–285 A. D. *The end of the pax Romana.* The period of fifty years from 235 to 285 A. D. is a prolonged repetition of the shorter epochs of civil war of 68–69 and 193–197 A. D. During this interval twenty-six Augusti, including such as were colleagues in the _imperium_, obtained recognition in Rome and of these only one escaped a violent death. In addition, there were numerous usurpers or “tyrants,” as candidates who failed to make good their claims to the principate were called. Almost all of these emperors were the nominees of the soldiery, and at least possessed military qualifications that were above the average. In general they conscientiously devoted themselves to the task of restoring order in the empire, but their efforts were in the main nullified by the treachery of their own troops and the rise of rival emperors.