Seleucid dynasty
The capture of Babylon in 312 by Seleucus marked the foundation of the Seleucid dynasty. Seleucid territory at its greatest extent was by far the largest of any of the Hellenistic kingdoms; with its centre in Syria, it ranged from western Turkey through to Afghanistan. But it lost territory, both in the East and in the West. In the East there were two problems. The mountainous province of Bactria (Afghanistan) was turned into an independent Greek kingdom (256 B.C.), and there also emerged the non-Greek kingdom of Parthia (c.238) which effectively blocked the Seleucids from the east. In the West the Seleucids also lost ground. A new Greek kingdom of the Attalids with its capital at Pergamum was carved out of Seleucid territory in western Turkey. Though the first two Attalids (283-241) had been only partially independent of the Seleucids, the victory of Attalus I over the Galatians (c.238) allowed him to assume the title of king. In the second century Attalid power was further increased by Rome, to whom the kingdom was bequeathed by the last king (133). The Seleucid kingdom itself by the first century B.C. had been reduced (partly because of internal dissension) to a small area of northern Syria, and it finally fell into the hands of Rome (64 B.C.). (Boardman, 1986)