Ptolemy Euergetes, the son of Philadelphus, having succeeded to his father's kingdom in the same year with Tiridates, marched (in B.C.

245) a huge expedition into Asia, defeated Seleucus II.

(Callinicus) in Syria, took Antioch, and then, having crossed the Euphrates, proceeded to bring the greater part of Western Asia under his sway.

Mesopotamia, Assyria, Babylonia, Susiana, Persia, Media, submitted to him.

He went in person as far as Babylon, and, according to his own account, was acknowledged as master by all the Eastern provinces to the very borders of Bactria.