III., grandson of Phraates IV., lived as a hostage in Rome and was educated there. When the Parthians rebelled against Artabanus II. in A.D. 35 they applied for a king to Tiberius, who sent Tiridates. With the assistance of L. Vitellius Tiridates entered Seleucia, but could not maintain himself long (Tacitus, Ann. vi. 32 sqq.; Dio Cass. lviii. 26).
The name Tiridates is also borne by some local kings of Persis, and by some Arsacid kings of Armenia and Georgia. The best known of the Armenian kings is the TIRIDATES (A.D. 238-314) who was baptized by Gregory the Illuminator (see ARMENIAN CHURCH). (ED. M.)