Arbil, (or Erbil or Irbil, known as Hewler in Kurdish), is one of Iraq's larger cities, located at 36.12N 44.01E about 80km (50 miles) east of Mosul. Its population was estimated in 1998 to be about 660,000 people.

The city is extremely ancient: its small archaeological museum contains only pre-Islamic objects. Urban life at the site dates at least to 2300 BC. The Aramaic name Arbile means "four gods" from the Semitic roots "arba" (4) and "ile" (god). During Assyrian times it was known as Arbela and was an important religious centre for the cult of the goddess Ishtar. Arbil was a part of the Persian Empire for many centuries. The town's name is sometimes given to the battle of October 1, 331 BC fought between Alexander of Macedon and Darius III of Persia, which actually took place at Gaugamela, some 100km (80 miles) away. It ended in a catastrophic defeat of the Persian forces and the absorption of Persia into Alexander's short-lived empire. After the Iranian revival under the Parthian and later the Sassanids, Arbil remained inside the Persian borders for many centuries more.

The current town of Arbil is located on a tell topped by an Ottoman fort. During the medieval period, Arbil became a major trading centre on the route between Baghdad and Mosul, a role which it still plays today with important road and rail links to the outside world.

The parliament of the Kurdish Autonomous Region was convened in Irbil for many years, but was effectively controlled by Saddam Hussein until the Kurdish uprising at the end of the 1991 Persian Gulf War. It effectively collapsed in the mid-1990s when fighting broke out between the two main Kurdish factions, the Kurdish Democratic Party (KDP) and the Patriotic Union of Kurdistan (PUK). The city was captured by the KDP in 1996 with the assistance of Saddam Hussein.

Irbil was fairly quiet during the 2003 invasion of Iraq. Although the United States had originally intended to use Kurdish and Turkish territory to mount an invasion from the north, this fell through after permission was denied by the Turkish parliament. The city was the scene of rapturous celebrations on April 10, 2003 after the fall of Baghdad. Following the war, the city experienced repeated bomb attacks against coalition forces and Kurdish targets. The worst of these was an attack on a joint PUK/KDP gathering on February 4, 2004 which killed 109 people and was blamed on the militant group Ansar al-Islam.