Editing Seleucus II Callinicus (section)

==Fragmentation in the East==
[[File:Syria - king Seleukos II - 261-246 BC - gold stater - head of Seleukos II - Apollon - München SMS.jpg|left|thumb|210x210px|Gold stater of Seleucus II. Antioch mint, c. 261-246 BC.]]
Seleucus then turned to the problems which had developed in the Eastern provinces of the empire over the last few decades and undertook an expedition to regain [[Parthia]], the results of which came to nothing.

The Parthian satrap [[Andragoras (Seleucid satrap)|Andragoras]] had taken the opportunity to establish de facto independence and had begun minting his own coins in 245 BC. However, before Seleucus was able to turn his attention eastwards, by 238 BC, Andragoras had been killed by [[Arsaces I of Parthia|Arsaces I]], a chieftain of the nomadic [[Parni]], based in the city of Nissa (modern day [[Nisa, Turkmenistan]]). Arsaces had previously attacked Bactria and been driven off by the satrap [[Diodotus I]].  Diodotus had also used the opportunity of Seleucid distraction in the West to gain de facto independence and set himself up as an independent ruler.

After the defeat at Ancyra, the Seleucid garrisons of the region were further weakened and this allowed the Parthians under Arsaces the opportunity to seize more territory, including the city of [[Qumis, Iran|Hekatompylos]], which became their new capital around 237 BC. Around this time Diodotus was succeeded by his son [[Diodotus II]] who agreed to an alliance with Parthia, which now acted as a useful barrier to any Seleucid invasion to recover the East.

It was after this that Seleucus attempted to recover Parthia, but the sources indicate he was defeated, or perhaps withdrew in the face of Parthian strength. The recovery of the Seleucid position in the East would have to wait until the reign of his son [[Antiochus III]]. Following this defeat Diodotus II declared himself king of Bactria, officially severing any remaining links with the Seleucid court in 235 BC.