the grandson of Phraates IV., king of Parthia, lived at Rome as a hostage, but was sent by the emperor Claudius, about A. D. 50, into Parthia at the request of the inhabitants, who were disgusted at the cruelty of their reigning sovereign Gotarzes. Cassius Longinus, the governor of Syria, received orders to support Meherdates in his attempt to gain the crown; but Meherdates was defeated in battle, and taken prisoner by Gotarzes, who spared his life but cut off his ears. (Tac. Ann. 11.10
The name Meherdates is merely another form of Mithridates.