At the same time, an unanticipated Parthian invasion of Syria led to the defeat of the Roman soldiers assigned there. Confident, Vologases IV declined an offer for peace by the Romans in 162. Although the Roman–Parthian War of 161–166 started auspiciously for the Parthians, after the Romans recovered from the first shock and setbacks, they counterattacked, restored Sohaemus to the Armenian throne in 163. Around the same time, the Parthians captured Edessa and installed Wa'el as puppet king. Ma'nu VIII, the legitimate king, was forced to flee to the Roman Empire. The Parthian forces were pushed out of Syria, in 164, and also lost Dura-Europos, which led many Parthian vassal rulers to desert Vologases IV. The Romans laid siege to Edessa in 165; during the siege, the citizens of the city massacred the Parthian garrison and opened its gates to the Romans. The Romans entered the city and restored Ma'nu VIII as ruler of Edessa/Osroene; he also received the epithet "Philorhomaios" ("Friend of the Romans").