The Seleucid Empire, based in Babylon and headed by Seleucus, also known as Nicator, was created out of part of Macedonian Empire, after the death of Alexander the Great. The Seleucid Dynasty ruled the area from 312-64 B.C. It covered Syria and a part of western Asia, with a capital at Antioch. At its height, extended from southern coast of modern Turkey south through Palestine and east to India’s border. It incorporated policies of the Achaemenid rulers in its policy, including using local people and satrapies for administration.
Although the Seleucids lost territory through the centuries, it came to an end when Pompey annexed Syria in 64 B.C.
The Seleucid Empire began when Seleucos I, one of Alexander the Great‘s former favorite companions was given the satrapy of Babylon in the second division of the empire in 321 BC. He first ruled it shortly until 315 BC, when he was forced to flee to Egypt under pressure of Antigonos. There he prepared his revenge with the help of Ptolemy, and succeeded to retake Babylon after the battle of Gaza in 305 BC. He also inherited the Asian part of Antigonos’ vast empire after its final fall at the battle of Ipsos in 301 BC. Having secured Antigonos’ kingdom’s eastern part, Seleucos managed to reconquer most of Alexander’s empire, defeating Lysimachos and Demetrios. He was, however, murdered in 281 BC on the eve of his success by the man he supported on the Egyptian throne, Ptolemy Keraunos.
After the Death of Seleucos, things became worse for his successors. During the successive reigns of Antiochos I, Antiochos II, Seleucos II and Seleucos III, the empire dilated itself, due to rebellions of Bythinia, Pergammum, Bactria and Parthia, and the first indecisive Syrian wars against the Ptolemies. Internal struggles began during this time, which continued until the empire’s end. The Seleucids also had to fight the Galatians who devastated Anatolia, and against rebellious elements at all levels.
It is this disorganized and problematic empire that the eighteen year-old Antiochos III inherited in 223 BC. Over the next 25 years he subdued most of the rebellious states in a great tour de force: He made his anabasis in the east successfully fighting Parthians and Bactrians, made a profitable treaty with the Indian ruler Sophagasenos and confirmed his superiority on rebellious subjects. He also made an expedition against the Gerrhaeans of the East Arabian coast in 204 BC and defeated the Ptolemies twice which allowed him to take control of the highly valued Koile Syria near 198 BC.
Regrettably, he also led a War against Rome in the wake of his expansion in Anatolia, and despite the wise advice of the Carthaginian Hannibal Barca, which he decided not to follow, he was defeated at the battle of Magnesia ad Sipylum in 190 BC. The consequences of the disastrous peace treaty which followed led the kingdom into ruin, and Antiochos III died in 187 BC during a campaign in the East.
Antiochos III’s death marked the end of the Seleucid Empire as a great power. The kingdom fell once more into dynastic struggles, and the eastern provinces were gradually lost due to rebellions and Parthian expansion. Much worse was the Roman interference in the Empire, largely influencing the dynastic quarrels and foreign policy, such as in 168 BC when the Romans forced Antiochos IV to withdraw from the only successful Seleucid campaign in Egypt. The wild intrigues which characterized the last decades of the Seleucid Empire were ended by the invasion of the Armenian king Tigranes II in 83 BC. Even if after Tigranes some rulers of Syria claimed to be Seleucid kings, they were no more than Roman vassals.
The Seleucid legacy in Asia was strong, because Hellenism was established in Asia during two centuries of Seleucid rule. The method of dating years in Asia, for example, was called the Seleucid Era, beginning at the return of Seleucos I to Babylon in 311 BC; which was continued to be used as late as the 6th century AD. In fact, the Seleucid legacy lasted throughout Roman, Parthian and Sassanid dominion until the Arabian invasions of the 7th century AD introduced Islam.