The Kingdom of Armenia between the Black Sea and Caspian Sea became a focus of contention between Rome and the Parthian Empire, and control of the region was repeatedly gained and lost. The Parthians forced Armenia into submission from 37 AD but in 47 AD the Romans retook control of the kingdom and offered it client kingdom status. Under Nero, the Romans fought a campaign between 55 and 63 AD against the Parthian Empire, which had again invaded Armenia. After gaining Armenia once more in 60 AD and subsequently losing it again in 62 AD, the Romans sent Gnaeus Domitius Corbulo in 63 AD into the territories of Vologases I of Parthia. Corbulo succeeded in returning Armenia to Roman client status, where it remained for the next century.