Balāš I, reigned ca. 51—ca. 76-80. He was a son of Vonones, king of Atropatene (Media), who was a brother of Artabanus II. Balāš I’s reign was remarkably long for a Parthian king, but fraught with internal and external difficulties. His attempt to obtain the throne of Armenia for his brother Tiridates in 53 inevitably gave concern to the Romans. (On Roman-Parthian conflicts over Armenia, see M. L. Chaumont, 1976, pp. 71ff.). The Roman-backed Armenian king Mithridates had been murdered in 52 by his nephew Radamistus, a son of Pharasmanes, king of Iberia, and the Parthians, taking advantage of the resultant disorder, marched into Armenia and placed Tiridates on the throne. The Romans at first had no choice except to negotiate, because their troops were then in a disorganized state, but the tide turned in their favor when civil war broke out among the Parthians. A revolt against Balāš I was launched in 55, or perhaps 54, by a prince who may have been a son of Vardanes I (opinion of Hanslik, col. 1841) or one of Balāš I’s own sons named Vardanes (opinion of Debevoise, p. 180, and many other scholars). Shortly after this, a rebellion in Hyrcania flared up. It seems likely that the two uprisings were connected; Vardanes may well have launched his revolt from Hyrcania. Balāš I consequently had to withdraw his troops from Armenia for action in Hyrcania. At the same time he accepted the Roman demands for peace and hostages. By delivering some Parthian princes as hostages to the Romans, he conveniently got rid of several potential rivals.

The chronology of the subsequent fighting over Armenia cannot be worked out with any precision, because Tacitus, our principal source, reports the events in four different passages in his Annals (13.34-41, 14.23-26, 16.1-17 and 24-31), each covering the events of several years, while the later historian Dio Cassius (80.19-23) gives only a general review of what happened. The Roman march into Armenia began not before the year 58. After conquering Artaxata, the capital, and later also Tigranokerta, and compelling Tiridates to flee, the Romans placed Tigranes V, a great-uncle of Archelaus, the last king of Cappadocia, on the Armenian throne. Before long, Tigranes invaded the adjacent principality of Adiabene, which was under Parthian suzerainty. It was now Balāš I’s turn to have to negotiate. An attack on a vassal of the Parthians by the Roman-appointed Tigranes was virtually an attack by the Romans themselves, and although Balāš’s adversary Vardanes had disappeared from the scene sometime around 58, the Hyrcanians maintained their formidable resistance. Balāš I therefore made peace with Hyrcania, which in effect meant that this province ceased to belong to the Parthian empire.

In any case Balāš was now in a position to intervene in Armenia itself. Military operations by both sides, with several breaks for parleys, ended in a success for Balāš. The Roman force, then under Caesennius Paetus who had taken over the command of the Armenian campaign from Corbulo, was surrounded by Balāš’s troops in its winter camp near Rhandeia on the Arsanias (Muratsu, a tributary of the Euphrates) and eventually had to capitulate at the end of the year 62. In the summer of 63, however, the Romans, who had in the meantime assembled another large force, again marched into Armenia. Recognizing the unlikelihood of Parthian victory in the war, Balāš I sent emissaries with peace proposals. The Romans advised him to apply to Nero at Rome for the grant of the Armenian throne to his brother Tiridates as a Roman vassal. Long delays followed before Tiridates finally set out in 66 on his famous journey to Rome, where he received his investiture as king of Armenia from Nero in a grandiose ceremony (described by Dio Cassius, 62, 63.5.2). The arrangement satisfied both sides. The Parthians were the real masters in Armenia but recognized the validity of the Roman claim to suzerainty over the kingdom (on the legal aspect of the arrangement, see Ziegler, p. 75).

Relations remained friendly until Nero’s death in 68, and Balāš strove thereafter to maintain peace. During the subsequent Roman civil wars, he proposed to send 40,000 mounted archers in support of Vespasian, but the latter gratefully declined the offer. The first discord arose after an invasion of the Parthian empire by Alan nomads, which began in 72. Balāš asked Vespasian for help against them in 75, but received the chilly response that “it would not be proper for the emperor to interfere in other people’s affairs” (Dio Cassius, 65, 66.15.3).

Balāš I died not long afterward, certainly not later than 80 (McDowell, pp. 119ff., 230), possibly as early as 76/77 (Le Rider, Suse, pp. 174-75) or 78 (Sellwood, p. 220). In this as in several other cases, the dating depends on the question to which Parthian king a small number of coins should be attributed.

Coins minted at Seleucia at the end of Balāš I’s reign bear not only the figure of Balāš but also that of a young man, the king Pacorus II (77-78; Le Rider, p. 175). This Pacorus appears to have been a son of Balāš; whether he was appointed co-regent or (as so often in Parthian history) came forth as a counter-king is uncertain. In any case the course of events in the following decades is impenetrably obscure.

In the Parthian context, Balāš I’s long reign deserves a measure of credit. The judgments of Kahrstedt (pp. 82-83) are too negative, those of Hanslik (col. 1847) and Keall (pp. 624ff.) are more positive. Balāš’s long tenure is in itself evidence of his diplomatic skill. Unlike many other Parthian rulers, he did not eliminate his kinsmen but gave them high offices and honors. The dispute over Armenia, always a bone of contention between the Romans and the Parthians, was settled on terms by no means unfavorable to Parthia. Balāš also found time to establish a new commercial center, Vologaisias, which evidently became an important town (Koshelenko, pp. 761ff.); identification of its site has not yet been possible, and the question whether the frequently mentioned town names Vologaisias and Vologesocerta refer to one and the same place (Maricq, pp. 264ff.) or two different places (Chaumont, 1974, pp. 77ff.) also remains unsolved.