During the long reign of his son Artaxerxes Lougiumuus (probably the Ahasuerus of Scripture), the power of the empire greatly declined ; Egypt was in continual revolt, and the Asiatic Greek cities were recognised as independent by the peace (449) which ended the Grecian war. The short reigns of Xerxes II. and Sogdianus occupy only a year (425) : and the rule of Darius II., surnamed Nothus (424-405), presents only revolts at home, and intrigues with Greece, where an alliance was formed with Sparta against Athens (411). Egypt threw off the yoke altogether in 414, and remained independent for 65 years. Artaxerxes 11., snrnamed Mnemon, succeeded (405.359); and his younger brother Cyrus, attempting to dethrone him by the aid of an army of Greek mercenaries, was defeated and killed (401) at the battle of Cunaxa, in the plains of Babylonia, an engagement which was followed by the memorable Retreat of the Ten Thousaud. In a war with Sparta, which commenced in 400, the integrity of the empire was threatened by the successes of Agesilaus, who, in three campaigns (396-94), advanced far into Asia: but by fomenting a coalition in tho heart of Greece against Sparta, Artaxerxes was enabled in 387 to conclude the advantageous peace of Antalcidas, by which Persia recovered the Ionian cities and Cyprus, though the latter was not reduced till after 10 yeare' war. The accession of his son Ochus, or Artaxerxea III., was followed by revolts in Asia Minor, Syria, and other provinces : but the former was betrayed by its loader Orontes and Syria was reduced (351) by Ochus in person, who destroyed Sidon, and advancing into Egypt, expelled the King Nectanebus, and reunited that country to the Persian empire (350). Ochus was poisoned by a eunuch named %goes, in B.C. 338. Bagoas now placed Armes, the only surviving son of Darius, on the throne, but murdered him two years afterwards, when the Male line of the royal family being extinct, he invested Darius IIi., Codomannus (a great-grandson of Darius Nothus), with the vacant dignity. This prince commenced his reign (336-30) by ridding himself of the traitor Bagoas : but the invasion of his dominions by Alexander the Great, in 384, left him little opportunity for the exercise of sovereignty. By three great battles (Granicus, 334; Issue, 333 ; and Arbela, 331) the Persian empire was utterly overthrown; and the unfortunate Darius, flying from the arms of Alexander, was murdered (330) by his own servants, while the whole extent of his dominions from the Hellespont to the Indus fell under the sway of the Macedonian conqueror.
On the death of Alexander (323) and the dismemberment of his vast territories by his generals, Persia fell to the la of the founder of the Syrian dynasty of the Seleucidx, Seleucue Nieator (312-280), and remained in subjection during his reign and that of his son Antiochna Soter (280-61). But in the reign of Antiochus Theos (261-48), a germ of independence reappeared in the foundation of the Parthian kingdom in the country of Hyrcania (Mazanderan) by Arsaces, the first of the house of the Arsaciche, of which 30 monarchs reigned in succession, each bearing the title of Arsaces, in addition to his individual name. One of these princes, Mithridates, or Pacorus 1. (174-136), extended the Parthian power to the Euphrates and the Indus, and in 138 took prisoner Detnetrins II. of Syria, who had invaded his territories. The away of Orodes I. (54-37), who had dethroned and put to death his brother Dlithridates III., was dis tinguished by the first war with Rome, and the defeat and slaughter of Crassus with his legions on the plain of Carrhas (53). On invading Syria and Asia Minor however, the Parthians were repulsed by Ventidiva (38); but this defeat was avenged by Phraates IV. (11.0. 37, to
A.D. 4) on Mark Antony, who only escaped from Pastille (no. 36) with the loss of the greater part of his army. Some years later however Plinistes opened diplomatic relations with Rome, and even sent his eons to be educated at the court of Augustus. The death of Phraates was followed by anarchy and dissension, and by wars with the Romans, at the close of one of which (A.D. 65), Tiridates, brother of Vologeses I., king of Perth's, accepted the Armenian kingdom as a fief of the Roman empire. Ctesiphon, the capital of the Parthinn empire, was taken and sacked by tho emperor Septimius Sever= in 1138; and these contests, though they occasioned no loss of territory, greatly weakened the declining monarchy. Artaxerxes, or Ardashlr, surnamed Babegan, a native of Fars, or Persia proper, overthrew the monarchy, and established the dynasty of the Sassanidx.
The reign of Artaxerxes, or Ardashlr Babegan, after he attained undivided power (226-42), was occupied, excepting a short war with the Roman", In regulating his new dominions, and re-establishing iu all its ancient splendour the Magian faith. His son Shahpoor, or Sapor I. (242-73), conquered Armenia, and by his victory, in 260, over the emperor Valerian (who was taken prisoner, with his army, and died in captivity), taught the Romans to respect and fear the arms of Persia. Syria. Cillcia, and Cappadocia were laid waste with ruthless severity ; Antioch was taken and plundered, but the latter part of his reign was left fortunate : Odenathtui, prince of Palmyra, and his celebrated wife Zenobia, defied his arms, and Aurelian re-established the Roman frontier in the Emt. .
War with the Romano however continued, and Karam (291.301), vindicated for • time the renown of the Persian arms by a signal victory (296) over Galerius; but in the next campaign the Persian forces were surprised and destroyed by the Romano, and by the peace concluded in 297, Names ceded Armenia and five provinces east of the Tigria. During the reign of Shahpoor or Sapor the Great the long war (337.63) was contested with the whole force of the two empire., and with varied success. In the battle of Singers (218) Shahpoor triotaphed over the emperor C,onstaatius; and the invasion of Persia by his successor Julian, which threatened the dismemberment of the kingdom, was frustrated by the death of that prince and the cowardice of his successor, who purchased • safe retreat by the peace of Dura (363), which restored Armenia and all the cessions made by Nerves. The wisdom of Shahpoor in government was equal to hie valour in war; • and the kingdom continued in peace and prosperity throughout the reigns of the three next monarchs. The reign of Iscligertes (Yezdejerd) in 401.21 was disturbed by religious dissensions ; the Magi murmured at the toleration and favour shown by the king to the Christians, and his friendship for the Oreek emperor Arcadian; bat the persecution of the Christians with which his son Bahratn V. commenced his reign, led to a short and Indecisive war with the Romans. The subsequent away of this prince was glorious and mular; after repulsing with great loss an invasion of the Turks of Trans-Oxiana, he extended his realm to the frontiers of India; and his extraordinary personal prowess has preserved his memory to the present, day in Persia as a favourite hero of romance, He perished accidentally in hunting. After a century of mingled prosperity, wars, and dimensions, the illustrious Khorsn Nuahervran (531.79), raised the Sassanian empire to its highest pinnacle of grandeur and prosperity.