A revitalised Parthian Empire renewed its assault in 161 AD, defeating two Roman armies and invading Armenia and Syria. Emperor Lucius Verus and general Gaius Avidius Cassius were sent in 162 AD to counter the resurgent Parthia. In this war, the Parthian city of Seleucia on the Tigris was destroyed and the palace at the capital Ctesiphon was burned to the ground by Avidius Cassius in 164 AD. The Parthians made peace but were forced to cede western Mesopotamia to the Romans.