The Parthian campaign of Antiochus VII, king of the Seleucid Empire, was an offensive to restore Seleucid rule in Mesopotamia and Persia. Antiochus led a large army to retake territories and quickly won three victories against the Parthians, capturing Babylonia and Media. By the spring of 129 BC, however, the conquered cities had risen in revolt against his garrisons. Marching to their relief, Antiochus led his army through the Zagros Mountains, where it was ambushed by the Parthian king Phraates II. Surrounded by the enemy, Antiochus was either killed in battle or took his own life. After his death, the territory of the Seleucids was limited to the area of Syria.
By 134 BCE, Parthian King Mithridates I had conquered the territories of Media, Babylonia, Elymais, and Characene, all previously ruled by the Seleucid Empire. After Mithridates's death in 132 BCE, Seleucid King Antiochus VII amassed a large force of Greek mercenaries, totaling 80,000 soldiers, to restore Seleucid rule over western Asia. By late 130 BCE, Antiochus defeated the Parthian general Indates along the Great Zab. To celebrate his victory, Antiochus built a tropaion, near the bank of the river Lycus. An uprising in Seleucia resulted in the death of the Parthian commander Enius, while Susa also came under Seleucid control as Antiochus advanced eastward.
Antiochus conquered Babylonia and Media, and for winter, divided his army into garrisons and quartered most of his army in Babylonia or Media.
Following Antiochus's victories against the Parthians, Phraates II, who had succeeded Mithridates I, sent envoys to Antiochus to negotiate peace. Antiochus refused unless the Parthians relinquished all lands to him except Parthia proper, paid heavy tribute, and released his brother Demetrius II from captivity. Phraates released Demetrius, but ignored the other demands.
Revolt
By October/November 129 BCE, the cities that Antiochus had conquered were in revolt. In response, Antiochus marched through the Zagros Mountains to relieve his garrisons, but his army was ambushed by the Parthian king Phraates II. Antiochus' commanders recommended that he withdraw to the protection of the mountain slopes. He instead chose to engage the Parthians and was subjected to hit and run tactics that hemmed in the Seleucids. By this point, the Seleucid troops started retreating, causing some of Antiochus's generals like Athenaeus of Macedonia to flee. As the battle deteriorated for the Seleucids, Antiochus and a select group of cavalry charged the Parthians and became isolated from the main army. The Parthians attacked Antiochus's group en masse and Antiochus was either killed or committed suicide to avoid capture.