to restore Parthian control of Armenia, prompting an aristocratic revolt that forced him to flee to Scythia. The Romans released a hostage prince, Tiridates III of Parthia, to rule the region as an ally of Rome. Shortly before his death, Artabanus managed to force Tiridates from the throne using troops from Hyrcania. After Artabanus' death in 38 AD, a long civil war ensued between the rightful successor Vardanes I and his brother Gotarzes II. After Vardanes was assassinated during a hunting expedition, the Parthian nobility appealed to Roman emperor Claudius (r. 41–54 AD) in 49 AD to release the hostage prince Meherdates to challenge Gotarzes. This backfired when Meherdates was betrayed by the governor of Edessa and Izates bar Monobaz of Adiabene; he was captured and sent to Gotarzes, where he was allowed to live after having his ears mutilated, an act that disqualified him from inheriting the throne. In 97 AD, the Chinese general Ban Chao, the Protector-General of the Western Regions, sent his emissary Gan Ying on a diplomatic mission to reach the Roman Empire. Gan visited the court of Pacorus II at Hecatompylos before departing towards Rome. He traveled as far west as the Persian Gulf, where Parthian authorities convinced him that an arduous sea voyage around the Arabian Peninsula was the only means to reach Rome. Discouraged by this, Gan Ying returned to the Han court and provided Emperor He of Han (r. 88–105 AD) with a detailed report on the Roman Empire based on oral accounts of his Parthian hosts. William Watson speculates that the Parthians would have been relieved at the failed efforts by the Han Empire to open diplomatic relations with Rome, especially after Ban Chao's military victories against the Xiongnu in eastern Central Asia. However, Chinese records maintain that a Roman embassy, perhaps only a group of Roman merchants, arrived at the Han capital Luoyang by way of Jiaozhi (northern Vietnam) in 166 AD, during the reigns of Marcus Aurelius (r. 161–180 AD) and Emperor Huan of Han (r. 146–168 AD). Although it could be coincidental, Antonine Roman golden medallions dated to the reigns of Marcus Aurelius and his predecessor Antoninus Pius have been discovered at Oc Eo, Vietnam (among other Roman artefacts in the Mekong Delta), a site that is one of the suggested locations for the port city of "Cattigara" along the Magnus Sinus (i.e. Gulf of Thailand and South