The Seleucids had suffered heavy defeats by the Iranian
Parthian Empire; in 148/7 BC, the Parthian king
Mithridates I () conquered
Media and
Atropatene, and by 141 BC, was in the possession of
Babylonia. The events are recorded in the Babylonian
astronomical Diaries. The menace and proximity of the Parthians caused Hyspaosines to declare independence. In 127 BC, Mithridates I's son and successor
Phraates II met an abrupt death during his war with the nomads in the east. Hyspaosines took advantage of the situation by seizing Babylon, which is attested in
Babylonian records, where he is recorded as king (
šarru). His rule over the city lasted briefly; at the start of November 127 BC, the Parthian general Timarchus recaptured it. Regardless, Hyspaosines' troops continued to plunder the Babylonian region as late as 126 BC. In 124 BC, however, Hyspaosines accepted Parthian suzerainty, and continued to rule Characene as a vassal. He corresponded with the Parthian general of Babylonia, informing him of the defeat of Elymais by the Parthian monarch
Mithridates II (). He also returned the wooden throne of
Arsaces to the Parthians as a gift to the god
Bel. The astronomical diaries report that the king became ill on 3 June 124 BC and died on 11 June 124 BC at the age of 85. His age is reported by 2nd century
Roman historian
Lucian, who provided a list of rulers who died in a very old age. He was succeeded by his and queen
Thalassia's juvenile son
Apodakos. The Parthian commander Sindates was placed as the governor of Characene. ==References==