Parthia, an ancient country of Asia, which for several hundred years was the seat of an extensive and powerful empire. Parthia proper was a territory S. E. of the Caspian sen, now embraced in the northern portion of the Persian province of Khorasan, with an area of about 83,000 sq. m. It was bounded N. W. by Hyrcania, N. by the territory of the Choras-mii (Kharesm or Khiva), N. E. by Margiana, E. by Aria, S. E. by Drangiana or Sarangia, and S. and W. by the territory of the Sagartii. The soil of the valleys is fertile, producing large crops of wheat, barley, rice, and cotton; the climate is severe in winter and hot in summer. The mountains are extensive, but of no great height, none of them exceeding 6,000 ft.; and besides many smaller streams there are three rivers of considerable size, including the upper course of the Tedjend. Parthia had no large cities. The chief was Hecatompylos, one of the cities founded by Alexander the Great, which when the Parthian kingdom Jiad expanded into an empire was abandoned by the sovereigns, though it always retained to some extent the distinction of being the national capital, and a royal palace was maintained there for the occasional reception of the court.

The site of Hecatompylos has not been ascertained, but it is supposed to have been near lat. 37° and Ion. 56° 80'. - The early history of the Parthians is very obscure. They are not mentioned at all in the Old Testament, nor in the Zend-Avesta, nor in the Assyrian inscriptions. In the inscriptions of Darius Hystas-pis (521-486 B. C.) Parthia is enumerated among the provinces of the Persian empire. The inhabitants were a brave and hardy peoEle, of Scythian origin, speaking a language alf Soythian, half Aryan, were armed in the Scythian fashion, and displayed extraordinary skill in horsemanship and in archery. Their armies consisted chiefly of cavalry, and their favorite weapon was the bow, with which they fought while in motion, using it as formidably in retreating as in advancing. Herodotus speaks of them as a people subject to the Persians in the reign of Darius, and as taking part in the expedition of Xerxes against Greece (480 B. C), armed with bows and with spears. They fought on the Persian side at Arbela against Alexander, and submitted to that conqueror without resistance after the death of Darius III. . On the division of Alexander's empire among his chief generals, Parthia came for a time under the rule of Antigonus, and subsequently under that of Seleucus, king of Syria, whose dominion extended from the Mediterranean to the Indus. His successors Anti-ochus I. and II. were almost constantly engaged in wars with their neighbors in Asia Minor and in Egypt, and paid little attention to the remote eastern provinces, which they governed by satraps in the Persian manner.

About 255 B. C. the satrap of Baetria, a Greek named Dio-dotus, revolted and proclaimed himself king. Antiochus II. made no effort to subdue him, and the independence of the new kingdom was established without bloodshed. A few years later (in 248, according to an inscription discovered by George Smith in 1874) Parthia followed the example of .Baetria, and became independent under a chief named Arsaees, of whom contradictory accounts are given by the ancient historians. According to one account, he was a Bactrian who would not submit to Diodotus, and going into Parthia induced the natives to revolt and make him their king. Another account says he was a Parthian of high rank, who, having been grossly insulted by the Greek satrap, killed him and headed a successful revolt. A third version says that Arsaces was a Scythian chief, who with a predatory band entered Parthia, drove out the Greeks, and made himself king with the consent of the natives, who hailed him as a deliverer. This version is accepted as most probable by George Rawlinson, the latest historian of Parthia. "Whatever his origin or however he acquired his power, Arsaces met with no opposition from Antiochus, and would have quickly established his rule but for malcontents, probably of Greek descent, in his new kingdom.

He struggled with them for two years, and fell in battle in 247 or 246. He was succeeded by his brother, who in addition to his own name, Tiridates, took that of Arsaces, as did all the Parthian kings down to the fall of the empire under Arsaces XXXIV. (or XXX.). Arsaces II. reigned upward of 30 years, consolidated the monarchy, enlarged its boundaries by the conquest of Hyrcania, and made it a united and powerful nation. He repelled a formidable army which the Syrian king Seleucus Callinicus led to Parthia in 237, the victory over which was long celebrated by the Parthians as the second beginning of their independence. Arsaces III., whose proper name was Artabanus, and whose reign began about 214, conquered Media, an aggression which led to immediate reprisals by the Syrian king Antiochus III., wno with a vast army retook Media, advanced into Parthia, and occupied Hecatompylos without opposition. He then invaded Hyrcania and captured several towns. The record of what followed has perished with the lost books of Polybius. It is only known that after a struggle of several years Antiochus retired about 206, having made a treaty acknowledging the independence of Parthia. For a considerable period after this Parthian history is almost a blank.

Phraates I. (Arsaces V.), an active and warlike king, conquered several provinces from the Syrian monarchy. After a reign of seven years he was succeeded by his brother Mithridates I. (Arsaces VI.), the most distinguished of the Parthian kings. During his long reign (174-136) the kingdom expanded by his conquests into a great empire, extending from the Euphrates to the Indus, and including, besides Parthia proper, Baetria, Aria, Margiana, I 11 yrcania, Media, Persia, and Babylonia. M ith-ridates met with little opposition from the Syrian kings whose eastern provinces he appropriated, because those monarchs were too much absorbed by civil warin Syriato attend to anything eke. But at length Demetrius If. so far suppressed his domestic enemies as to deem it prudent to undertake a campaign against the Parthians, who had now passed the Euphrates and were threatening Syria itself. He was received as a deliverer by the Greeks who occupied the cities, and who hated the Parthian conquerors; and with their aid and that of disaffected Persians and Bactrians, he won many battles at first, but was finally defeated in a great battle in which his army was destroyed and himself taken prisoner.

Soon after this victory Mithridates died, and was succeeded by his son Phraates II. (Arsaces VII.). Antiochus Sidetes, the brother of Demetrius, had become king of Syria on the captivity of the latter, and in 129 undertook to rescue the captive king and to chastise the Parthians. He accordingly crossed the Euphrates with a vast army, which at first met with some success, but was at last totally defeated and destroyed, Antiochus himself being killed. The Parthian king Phraates did not long survive his victory; ho became involved in a war with the Scythian nomads on his northern frontier, and was defeated and slain by them in 127. His successor Artabanus II. (Arsaces VIII.) met with the same fate about throe years later. Mithridates II., called the Great by ancient writers, repelled the Scythian hordes and added to the empire many provinces on its northern side. He also invaded Armenia, which brought him into contact with the Romans. Ho probably died about 89, after a reign of 85 years. A period of civil war seems to have followed, during which negotiations with the Romans were earned on with regard to Armenia, and a sort of alliance was formed between the Roman general Pornpey and a Parthian king named Phraates III., who was assassinated by his sons Mithridates and Orodes about 60. Mithridates became king, but was deposed and put to death by Orodes about 55. In that year Crassus became consul at Rome, and being appointed to the command of the East announced his intention of conquering Parthia. After a reconnoissance in force beyond the Euphrates in 54, he entered on his great campaign in 58 with a powerful army, which was totally defeated by the surena or general of Orodes near Carrhffl in Mesopotamia. Crassus escaped from the battle, but was soon after entrapped into a conference and put to death.

Of his army three fourths were killed or captured. The victorious Parthians now invaded Syria, which had become a Roman province; but as their force was chiefly cavalry, they could not capture any of the cities, and were easily expelled from the country by Cassius the proconsul. Subsequently Orodes took part in the civil war that followed the death of Caesar, by sending a body of cavalry to the aid of Brutus and Cassius; and in 40, having the aid of a Roman soldier of much experience, Labi-enus, one of the defeated party, he sent a great force to invade Syria under the joint command of Labienus and his own son Pncorus. The Parthians under Pacorus overran Syria, Phoenicia, and Palestine, in the last named country setting up Antigonus, an Asmonean prince, as priest-king, who governed Jerusalem for three years (40-37) as a Parthian satrap. Meanwhile Labienus with a portion of the Parthian army invaded Asia Minor, defeated and slew the Roman general who opposed him, and conquered Oilicia, Pamphylia, Lycia, and Caria, and it is said pillaged even Lydia and Ionia. For about a year the Parthians were undisputed masters of Asia, and Roman authority had disappeared.

But in 39 Antony sent his lieutenant Ventidius with an army to the East. He landed on the coast of Asia Minor, and presently defeated and dispersed the invaders, capturing Labienus and putting him to death. He then turned his arms against Pacorus, defeated a Parthian force at the Syrian Grates, reconquered Syria, and drove Pacorus across the Euphrates in 39 or 38. The next year Pacorus recrossed the Euphrates with a powerful army, but was met by Ventidius and defeated and slain. His father Orodes, overwhelmed with grief, resigned the throne to his second son Phraates IV., w,ho soon put him to death, killed his 30 brothers, and persecuted the Parthian nobles so severely that most of them fled into the neighboring countries. A body of them took refuge in Syria, where Antony was now in command, and persuaded him to invade Parthia. He began his invasion in 37 with a force of more than 100,000 men, whom he led through Armenia into Media. His expedition failed, and he was compelled to retreat with the loss of a third of his army. In 20 the emperor Augustus visited the East, and persuaded Phraates to restore to him the standards taken from Orassus, which were received in Rome with extravagant delight.

After the death of Phraates, who was poisoned by his wife and son about the beginning of the Christian era, the history of Parthia for more than a century seems to have been chiefly a succession of revolutions and civil wars, ending in a disintegration of the empire, so that three or four monarchs, each claiming to be the true Arsaces, were ruling at the same time in different portions of the Parthian dominions. The Romans knew little of these divisions, their dealings being only with the Arsaces who reigned at Otesiphon over Mesopotamia and Adiabene. About A. D. 108 the Arsaces at Otesiphon bore the name Chosroes, and his nephew a few years before had been made king of Armenia by the Parthians without consulting the Romans, who had long claimed the right to nominate the occupant of the Armenian throne. Trajan, who was then emperor, having the Dacian war on his hands, had borne this insult without seeking redress until the subjugation of Dacia left him free to act. He then resolved on the conquest of Parthia, and in 114, after long preparation, began his expedition. Envoys of Chosroes met him at Athens with conciliatory proposals, which he rejected. He. continued his march to Armenia, which submitted with little resistance and was declared a Roman province.

The conquest of Mesopotamia speedily followed, together with that of some adjacent territories; but the natives were so turbulent and harassed the Romans so much that Trajan, who had occupied Otesiphon, found it prudent to retreat into Syria at the end of 116. In the following year he was taken ill, and leaving Hadrian in command in Syria he set out for Rome, but died on his way in Cilicia. Hadrian, who succeeded him as emperor, relinquished the conquests of Trajan and withdrew the Roman forces to the west side of the Euphrates. Peace between Rome and Parthia lasted till 161, when the Parthian king Volo-geses III. on the death of Antoninus Pius suddenly invaded the Roman territories, conquered Armenia, and carried fire and sword through Syria into Palestine. Lucius Verus went to the East, and the Roman army, commanded by Avidius Oassius, defeated Volo-geses in a great battle near the Euphrates and drove the Parthians across that river. Cassius then carried the war into Parthia. He captured and burnt the great city of Seleucia, plundered Otesiphon, and recovered all the conquests of Trajan. The war with Rome terminated in 165, and peace between the two empires was maintained till the commotions which followed the murder of Commodus in 192 excited the Parthians of the provinces annexed by Cassius to rise in insurrection and massacre the Roman garrisons, and to besiege Nisibis, the Roman capital of Mesopotamia. The emperor Septimius Severus marched in 195 to the relief of Nisibis, reduced Mesopotamia to subjection, and added Adiabene to the empire.

In the following year he returned to Rome to suppress the insurrection of Clo-dius Albinus, who had been proclaimed emperor. On his departure the Parthians renewed hostilities, recovered Adiabene, swept the Romans from Mesopotamia or shut them up in Nisibis, to which they laid siege, and even invaded Syria. Severus, having suppressed and slain his rival, returned to the East in 197, drove the Parthians across the Euphrates, which he himself passed with a powerful army, captured Babylon and Seleucia, and, after defeating the Parthian king in a great battle before the walls of Otesiphon, took that capital by assault, gave it up to plunder, and before returning to Italy established a new Roman province in the region beyond the Tigris. His son Oaracalla renewed the war, and after a campaign beyond the Tigris went into winter quarters at Edessa, but was assassinated in April, 217, by one of his officers. Macrinus, who succeeded to the command of the army and was proclaimed emperor, began to retreat toward Syria, but was attacked by Artabanus IV. (Arsaces XXXIV.), the last and one of the ablest of the Parthian kings. The Romans stood at bay at Nisibis, and the battle which ensued was the last and fiercest ever fought between the forces of the two great empires.

It lasted three days, and resulted in the defeat of the Eomans, who were compelled to purchase permission to retire unmolested at a price equivalent to about $7,000,000. Three or four years after this great battle Artaxerxes, the tributary king or satrap of Persia, who claimed descent from Cyrus and Darius Hystaspis, revolted against Artabanus, called the Persians and the followers of Zoroaster to arms, and, after a hard struggle which lasted five or six years, defeated and killed Artabanus in a great battle on the plain of Hormuz in 226. The Parthian empire thus perished after an existence of nearly five centuries, and the Persian empire of the Sassanians took its place. - See "The Sixth Great Oriental Monarchy," by George Rawlinson (London, 1873).