Vologases III of Parthia

Vologases III of Parthia, who ruled from 110 to 147, was the son and successor of Pacorus II. His reign was characterized by significant civil strife and military challenges, particularly from usurpers and external forces.

Upon ascending the throne, Vologases III faced the immediate threat of Osroes I, who had seized control of the western territories of the Parthian Empire. This left Vologases III to govern the eastern regions, where he would later capitalize on Osroes I's weakened position following a series of conflicts.

The tensions escalated when Osroes I breached the Treaty of Rhandeia by appointing Parthamasiris as king of Armenia in 113, prompting a Roman invasion led by Emperor Trajan. The Romans briefly captured key Parthian cities, including Seleucia and Ctesiphon, and advanced towards the Persian Gulf. However, these territorial gains were short-lived, as they were lost after Trajan's death in 117.

With his eastern domains intact, Vologases III regained lost territories and ultimately defeated Osroes I in 129. He also faced challenges from another contender, Mithridates V, whom he defeated in 140. Additionally, Vologases III dealt with invasions from the nomadic Alans between 134 and 136, while also responding to the expansion of the Kushan Empire.

During the reign of Emperor Antoninus Pius, disturbances arose in Armenia due to Roman interference. Vologases III chose not to contest this, possibly to protect the lucrative long-distance trade that benefited the Parthian economy. His reign concluded with his succession by Mithridates V's son, Vologases IV, in 147.