114-117 AD., Trajan, Rome mint, Sestertius, RIC 667.

Trajan, Rome mint, 114-117 AD.,
Sestertius (ø 33 mm / 25,85 g), brass ("orichalcum"), axes about coin alignment ↑↓ (ca. 160°), flan crack at four o’clock on obverse,
Obv.: [IMP CAES NER TRA]IANO OPTIMO AVG GER DAC PARTHICO P M TR P [C]OS VI P P , his laureate and draped bust right.
Rev.: [RE]X [PAR]THIS DATVS / S C , Trajan seated left on high platform accompanied by officer, placing diadem on the head of king Parthamaspates who stands before him beside platform; Parthia kneeling right in supplication before.
RIC 667 (R) ; BMC 1046 ; CBN 920 ; Coh. 328 (20 Fr.) ; Woytek 594v2 (134 spec.) .

In 114 AD. trouble began with the Parthians on the eastern frontier of the Roman empire. The Parthians placed their own nominee in Armenia as king, thereby upsetting the balance of power that existed in the East with Armenia acting as a buffer-state between Rome and Parthia. Trajan responded with military force; he annexed Armenia as another Roman province and then extended operations into Mesopotamia. By 116, he had conquered the whole of Mesopotamia, including the Parthian capital of Ctesiphon. Trajan's intervention in Parthian affairs proved short-lived. The rival kings Vologases III and Osroes I continued to fight for the throne, and Parthamaspates' role as Roman puppet did not last beyond the withdrawal of the legions from Parthian territory after Trajan's death in 117 AD. Hadrian finally installed him as a minor king in Armenia.

The reverse depicts the investiture of Parthamaspates as king of Parthia in AD 116. He was to enjoy his position for only a short time, as Roman forces soon after withdrew from Parthia and Trajan died the following year. After Trajan defeated the Parthians in 116, he installed Parthamaspates on the Parthian throne as a client of Rome. The intention was to create a buffer zone between Roman territory and areas further east. Soon after Trajan's death, however, the Romans withdrawal from the area and the Parthians regrouped under Parthamaspates' father, Osroes I, who reclaimed the kingdom. Parthamaspates fled to Rome and was subsequently made co-ruler of the Roman client kingdom of Osroene, which he ruled until 123. The reverse of this coin commemorates Parthmaspates' installment on the throne of Parthia by Trajan. We see here the personification of Parthia kneeling before the emperor, and Trajan, who is seated on a suggestum and attended by the commander of the Praetorian guards, presenting Parthamaspates whom he points to with his hand. This event is attested by legend REX PARTHIS DATVS - 'A King given to the Parthians'.