Tetradrachm - Demetrius II Nicator Seleucia on the Tigris

Demetrius II retook the Seleucid throne from the usurper Alexander Balas in 145 BC with Ptolemaic backing — his father-in-law Ptolemy VI died in the same campaign — and immediately faced the eastern problem that had plagued the dynasty for decades. These Seleucia-on-Tigris issues date to precisely the window before the Parthians under Mithridates I drove him out of Mesopotamia entirely, capturing Demetrius himself around 141 BC. He spent roughly a decade as a Parthian prisoner, an episode almost without parallel among Hellenistic monarchs.