Seleucid Empire - An Overextended Domain

An Overextended Domain

Nevertheless, even before Seleucus' death, it was difficult to assert control over the vast eastern domains of the Seleucids. Seleucus invaded India (modern Punjab Pakistan) in 305 BC, confronting Chandragupta Maurya (Sandrokottos), founder of the Maurya empire. It is said that Chandragupta fielded an army of 600,000 men and 9,000 war elephants (Pliny, Natural History VI, 22.4).

Mainstream scholarship asserts that Chandragupta received vast territory, sealed in a treaty, west of the Indus, including the Hindu Kush, modern day Afghanistan, and the Balochistan province of Pakistan. Archaeologically, concrete indications of Mauryan rule, such as the inscriptions of the Edicts of Ashoka, are known as far as Kandahar in southern Afghanistan.

It is generally thought that Chandragupta married Seleucus's daughter, or a Macedonian princess, a gift from Seleucus to formalize an alliance. In a return gesture, Chandragupta sent 500 war-elephants, a military asset which would play a decisive role at the Battle of Ipsus in 301 BC. In addition to this treaty, Seleucus dispatched an ambassador, Megasthenes, to Chandragupta, and later Deimakos to his son Bindusara, at the Mauryan court at Pataliputra (modern Patna in Bihar state). Megasthenes wrote detailed descriptions of India and Chandragupta's reign, which have been partly preserved to us through Diodorus Siculus. Later Ptolemy II Philadelphus, the ruler of Ptolemaic Egypt and contemporary of Ashoka the Great, is also recorded by Pliny the Elder as having sent an ambassador named Dionysius to the Mauryan court.

Other territories lost before Seleucus' death were Gedrosia in the south-east of the Iranian plateau, and, to the north of this, Arachosia on the west bank of the Indus River.

Antiochus I (reigned 281–261 BC) and his son and successor Antiochus II Theos (reigned 261–246 BC) were faced with challenges in the west, including repeated wars with Ptolemy II and a Celtic invasion of Asia Minor — distracting attention from holding the eastern portions of the Empire together. Towards the end of Antiochus II's reign, various provinces simultaneously asserted their independence, such as Bactria under Diodotus, Parthia under Arsaces, and Cappadocia under Ariarathes III.

Diodotus, governor for the Bactrian territory, asserted independence in around 245 BC, although the exact date is far from certain, to form the Greco-Bactrian kingdom. This kingdom was characterized by a rich Hellenistic culture, and was to continue its domination of Bactria until around 125 BC, when it was overrun by the invasion of northern nomads. One of the Greco-Bactrian kings, Demetrius I of Bactria, invaded India around 180 BC to form the Greco-Indian kingdom, lasting until around AD 20.

The Seleucid satrap of Parthia, named Andragoras, first claimed independence, in a parallel to the secession of his Bactrian neighbour. Soon after however, a Parthian tribal chief called Arsaces invaded the Parthian territory around 238 BC to form the Arsacid Dynasty — the starting point of the powerful Parthian Empire.

By the time Antiochus II's son Seleucus II Callinicus came to the throne around 246 BC, the Seleucids seemed to be at a low ebb indeed. Seleucus II was soon dramatically defeated in the Third Syrian War against Ptolemy III of Egypt and then had to fight a civil war against his own brother Antiochus Hierax. Taking advantage of this distraction, Bactria and Parthia seceded from the empire. In Asia Minor too, the Seleucid dynasty seemed to be losing control — Gauls had fully established themselves in Galatia, semi-independent semi-Hellenized kingdoms had sprung up in Bithynia, Pontus, and Cappadocia, and the city of Pergamum in the west was asserting its independence under the Attalid Dynasty.