Antiochus VII Sidetes

Antiochus VII Sidetes (ruled 138–129 BC) was the last Seleucid ruler of any stature. His epithet 'Sidetes' comes from the city of Side, where he was raised. He took the throne after his brother Demetrius II was captured by the Parthians, facing the usurper Diodotus Tryphon whom he defeated to reunite the crumbling empire.

The Last Great Campaign

Antiochus VII is best known for his ambitious campaign to reclaim the lost eastern provinces from the Parthian Empire. He gathered a massive army and marched east, achieving initial successes:

• Reconquest of Mesopotamia: He successfully drove the Parthians out of Babylonia and Media in three successive battles.
• Siege of Jerusalem (134 BC): Before turning east, he besieged Jerusalem and forced the Hasmonean ruler John Hyrcanus to pay tribute, reasserting Seleucid authority over Judea.

Defeat and Death

Despite his victories, the campaign ended in disaster. In the winter of 129 BC, his troops were scattered across Media for winter quarters. The local population, burdened by the army's presence, rose in revolt encouraged by the Parthians. The Parthian king Phraates II launched a surprise attack. Antiochus VII, refusing to flee, was killed in the Battle of Ecbatana.

Legacy

With his death, the Seleucid Empire lost its last chance to remain a great power. It was henceforth reduced to a local Syrian kingdom, plagued by endless dynastic feuds until its final annexation by Rome.