In his nine-year reign, Antiochos strove with some success to reverse the massive territorial and authority losses of the previous decades. Of the numerous wars he waged to this end, only the one against the Maccabean independence movement in Palestine is known in more detail. This conflict resulted in a siege of Jerusalem lasting several months, which was ended with a compromise. In the peace treaty concluded, the Jews were able to maintain their internal autonomy, but were firmly reintegrated into the Seleucid Empire.
In 131 BC, Antiochos finally began a large-scale campaign against the Parthian Arsacids, the most aggressive enemies of the Seleucid Empire at the time, who had conquered economically very important Mesopotamia a few years earlier. The military advance was initially extremely successful: in the first year of the war, his army brought Mesopotamia back under its control, and in the second it advanced as far as the Parthian heartland southeast of the Caspian Sea. Antiochos rejected a peace offer from the Arsacids. This proved to be a mistake. While his soldiers were decentralised into winter camps, the Parthian king Phraates II organised a joint uprising of many cities in the region and then led his counter-attack, in which the militarily now much weaker Antiochos was defeated and lost his life. His brother Demetrios, whom Phraates had released shortly before, probably for tactical reasons, then entered his second reign in the Seleucid Empire. In the following years, however, the empire shrank again to a comparatively small area in Syria, Cilicia and Coilesyria.
Nikephoros (Greek: "victory bringer", from nike "victory" and phoreo "bring, carry", Latin form: Nikephorus or Nicephorus) is an epithet of the Greek goddess Athena.