Shortly after Nero 's accession to the throne in 54 , the Roman vassal kingdom of Armenia overthrew their Iberian prince Rhadamistus and he was replaced with the Parthian prince Tiridates . This was seen as a Parthian invasion of Roman territory . There was concern in Rome over how the young Emperor would handle the situation . Nero reacted by immediately sending the military to the region under the command of Gnaeus Domitius Corbulo . The Parthians temporarily relinquished control of Armenia to Rome .