PARTHIANS. - A people of the Iranian group, living between the Caspian and the central Persian desert (the northern part of present-day Khorasan): the Parthava of the inscriptions of Darius, the Παρθωσία of the Greeks. They enter history in the 3rd century B.C., from the remains of the great Empire of Alexander, which had succeeded the Persian one. The Parthians identified themselves, at least partially, with the Persians (v.), and the Roman writers of the Empire regarded them as such. The first king, Arsaces, having killed (248-247 B.C.) the satrap Andragoras, representative of the Seleucids of Syria, founded the Parthian Kingdom, beginning the Arsacid dynasty that guided its fortunes until 224 A.D.
Vain were the repeated attempts of the Seleucids to subjugate the young Kingdom, or at least to check its conquering drive toward the west (already Seleucus II in 238 B.C.), principally under Mithridates, brother and successor of Phraates I, who in his long reign (174-136 B.C.) conquered Media, Elymais, Persia, Babylonia, annexed Adiabene (Assyria), and in 142 was proclaimed "king of kings," the ancient title of the Persian emperors. Antiochus IV Epiphanes (164 B.C.) died in an expedition against the Parthians; in another Demetrius II (140 B.C.) was defeated and fell prisoner. Antiochus VII in 130 B.C. attacked Phraates II, son and successor of Mithridates, to free his brother Demetrius and drive the Parthians back from the eastern provinces of the Kingdom; after initial successes and the liberation of Demetrius, in 129, while he was advancing on Ecbatana and the troops were somewhat scattered, he was defeated by the Parthians and killed; in that campaign Antiochus had the help of a Jewish contingent, commanded by John Hyrcanus himself, who immediately afterward returned to Jerusalem. During the fratricidal war between Antiochus VIII and Antiochus IX (111-95 B.C.), the Parthians pushed toward the Mediterranean. With Phraates II (64-57 B.C.) they enter into contact with Roman arms, which they would always boldly withstand, commanded by valiant generals-in-chief, to whom they gave the title of suren. Under Orodes II (56-37 B.C.), son of the previous king, the Parthians inflicted on the Romans of Crassus, proconsul of Syria who lost his life there, the grave defeat of Carrhae (53 B.C.), captured the standards and numerous prisoners; at that time they dominated all of Mesopotamia, and moved their capital to Ctesiphon. In 50 B.C., having done away with the suren out of the King's envy, and with the prince Pacorus killed in battle, the Parthians fell back to the Euphrates. Soon, however, during the civil wars that shook Rome, the Parthians advanced menacingly; an army led by Q. Labienus invaded Asia Minor, another under the command of the king's firstborn, Pacorus, and of the satrap Barzapharnes, overran Syria-Palestine (40 B.C.), while Antony abandoned the legions to follow Cleopatra in Egypt. Antigonus (v.), the last of the Hasmoneans, made use of the Parthians, masters of Galilee, to depose Hyrcanus, who remained for some time a prisoner of the Parthians in Babylonia, while Herod fled and obtained the kingdom and the high priesthood (40-37 B.C.). But in 39 B.C., P. Ventidius repelled the Parthians among the gorges of the Taurus and drove them back from Syria, defeating them definitively in Sept. 38 B.C. Herod, with the help of the Romans, could thus win for himself (37 B.C.) the kingdom given to him in 40 by Antony and Octavian. Once Antony's campaign (36 B.C.) against the Parthians ended at its very beginning, there was a peaceful interlude. Phraates IV, successor of Orodes, sent to Augustus (20 B.C.) the Roman standards captured from Crassus, returned the prisoners and had his own sons educated in Rome. With Artabanus III (10-40 A.D.) hostilities resumed, on account of Armenia. Tiberius sent Germanicus to support his protégé Zeno against the Parthians. Later, Vologases I placed his brother Tiridates on the Armenian throne, and the latter refused to request investiture from Rome. Nero sent Domitius Corbulo (59 A.D.), who defeated Tiridates and occupied all of Armenia; but Vologases I attacked and routed the Romans, left under the command of Caesennius Paetus. Only the return of Corbulo (62 A.D.) allowed the Romans to impose honorable conditions (63).
Thus in 66 A.D. Tiridates, with his sons and accompanied by 3000 horsemen, went to Rome, where he received from Nero, with solemn pomp in the forum, the investiture of the Kingdom of Armenia. The journey was not made by sea, because, being Zoroastrians ("magi"), they were prevented from it by religious scruples (Tacitus, Ann., 15, 29; Pliny, Nat. hist., 30, 2, 16; Cassius Dio, Hist. Rom., 63, 5). The investiture marked the beginning of a Parthian dynasty in Armenia, which lasted 362 years. It is not comprehensible how it could have been insinuated (E. Klostermann, E. Herzfeld) that the account of the aforementioned journey, with the ceremony of investiture, inspired the Gospel narrative of the coming of the Magi to Bethlehem. Even setting aside the chronological difficulty, there is not a single element that could ground or explain such an influence (G. Messina, I Magi a Betlemme, Rome 1933, p. 6 ff.).
Acts 2:9 speaks of a Jewish diaspora in Parthia; and one may think of the presence of converts to Christianity returning from the extraordinary Pentecost they had witnessed. The campaigns against the Parthians (114-116) of the emperor Trajan ("the Parthian") are famous; while he was at Ctesiphon the revolt of the Jews in Mesopotamia broke out, energetically repressed by L. Quietus. But even Trajan was forced to withdraw and died in Cilicia. The campaigns of Marcus Aurelius and Septimius Severus, who in 199 A.D. sacked Ctesiphon, had an equal outcome. During these wars the Parthians favorably welcomed, for political reasons, many Christians, who were fleeing from the Empire because of the persecutions. The exact opposite would happen after the legal recognition of the Church by Constantine: the Sassanid dynasty, dominated by the magi, would ferociously persecute the Christians.
The last splendor of the Arsacid dynasty came with Artabanus V; Caracalla, while moving against him, was killed at Edessa (214 A.D.) and the army, then led by Macrinus, was twice beaten and forced to make peace. The rebellion of Ardashir (224 A.D.), a Persian who occupied Ctesiphon, began the new Persian dynasty called Sassanid, from Sasan, grandfather of Ardashir.