Ahvaz is the capital city of Khuzestan province in the south-west of Iran. It is situated on both banks of the Karun River where it crosses a low range of sandstone hills. The town has been identified with Achaemenid Tareiana, a river crossing on the royal road connecting Susa, Persepolis, and Pasargadae. Ardashir I, the Sasanian king (224–241 AD) who rebuilt the town, named it Hormuzd Ardashir. He dammed the river, providing irrigation water, and the town prospered.
When the Muslim Arabs conquered it in the 7th century, they renamed it Suq al-Ahwaz (“Market of the Ahwaz”). Ahwaz is the Arabic name for the Huzi (or Khuzi), a local warlike tribe that gave its name to the historical region of Khuzestan. Arab historians of the 12th century described Ahwaz as the centre of a large sugarcane and rice-growing area irrigated by a system of great canals from a dam constructed across the river on solid rock.
Ahvaz had begun to decline in the 19th century when the dam collapsed and nearly destroyed the town. The discovery of oil in Khuzestan in the 20th century brought new prosperity to Ahvaz. Because of its location near the border with Iraq, Ahvaz was heavily bombarded during the Iran-Iraq War (1980–88). Nonetheless, a steel complex west of the town began operating in 1989.
Ahvaz is at a junction of two branches of the Trans-Iranian Railway. It is also connected with Abadan, Khorramshahr, Shushtar, Dezful, and the oil fields by road and with Tehran by air.