Arbela (Akkadian Arbirâ): A town in ancient Assyria, modern Arbîl or Erbil (its real name was Arba'ilu), situated on the east bank of the Tigris. Archaeological discoveries have confirmed the existence of a Persian garrison in the fourth city BC. In 331 BC, the Persian king Darius III used Arbela as his base before he marched to Gaugamela, where he was defeated by his Macedonian colleague Alexander the Great.