305 BCE
Seleucus Founds Seleucia
About this moment
Seleucia (Ancient Greek: Σελεύκεια), also known as Seleucia-on-Tigris, Seleucia on the Tigris or Seleucia ad Tigrim, was a major Mesopotamian city, located on the west bank of the Tigris River within the present-day Baghdad Governorate in Iraq. It was founded around 305 BC by Seleucus I Nicator as the first capital of the Seleucid Empire, and remained an important center of trade and Hellenistic culture after the imperial capital relocated to Antioch. The city continued to flourish under Parthian rule beginning in 141 BC; ancient texts claim that it reached a population of 600,000.