Seleucid Empire
The Seleucid Empire ( sih-LEW-sid) was a Greek state in West Asia during the Hellenistic period. It was founded in 312 BC by the Macedonian general Seleucus I Nicator, following the division of the Macedonian Empire founded by Alexander the Great, and ruled by the Seleucid dynasty until its annexation by the Roman Republic under Pompey in 63 BC. After receiving the Mesopotamian regions of Babylonia and Assyria in 321 BC, Seleucus I began expanding his dominions to include the Near Eastern territories that include modern-day Iraq, Iran, Afghanistan, Syria, and Lebanon, all of which had been under Macedonian control after the fall of the former Achaemenid Empire.