the son and successor of the preceding, is called by Justin Theodotus, as well as his father. According to that author, he abandoned his father's policy, and concluded a treaty with the king of Parthia, Tiridates, by which he joined him against Seleucus Callinicus. (Just. 41.4.) The total defeat of the Syrian king probably secured the independence of Bactria, as well as that of Parthia; but we know nothing more of the history of Diodotus. The commencement of his reign may be dated somewhere about 240 B. C. (Wilson's Ariana, p. 217.)