 Complete the following phrase:  The Romans fought a prolonged and indecisive campaign in the East against the Parthians beginning in 53 BC, commencing with the defeat of Marcus Licinius Crassus close benefactor of Julius Caesar and his 35,000 legionaries at Carrhae. This initially unexpected and humiliating defeat for Rome was followed by numerous campaigns over the next two centuries entailing many notable engagements such as: the Battle of Cilician Gates, 