Shatt al-Arab

The Shatt al-Arab (Arabic: شط العرب, lit. 'River of the Arabs') is a river about 200 kilometres (120 mi) in length that is formed at the confluence of the Euphrates and Tigris rivers in the town of al-Qurnah in the Basra Governorate of southern Iraq. The southern end of the river constitutes the Iran–Iraq border down to its mouth, where it discharges into the Persian Gulf. The Shatt al-Arab varies in width from about 232 metres (761 ft) at Basra to 800 metres (2,600 ft) at its mouth. It is thought that the waterway formed relatively recently in geological time, with the Tigris and Euphrates originally emptying into the Persian Gulf via a channel further to the west. Kuwait's Bubiyan Island is part of the Shatt al-Arab delta.

The Karun, a tributary which joins the waterway from the Iranian side, deposits large amounts of silt into the river; this necessitates continuous dredging to keep it navigable.

The area used to hold the largest date palm forest in the world. In the mid-1970s, the region included 17–18 million date palms: an estimated one-fifth of the world's 90 million palm trees. However, by 2002, more than 14 million of the palms had been wiped out by the combined factors of war, salt and pests; this count includes around 9 million palms in Iraq and 5 million in Iran. Many of the remaining 3–4 million trees are in poor health.

The river is also known in Iraq as the Dijla al-Awara (دجلة العوراء) and in Iran as the Arvand Rud (Persian: اروندرود, lit. 'Valiant River').

The Persian epic poem Shahnameh (written between c. 977–1010 CE) and many other works of Middle Persian literature use the name Arvand (اروند) for the Tigris River, the confluent of the Shatt al-Arab. Iranians also used this name specifically to designate the Shatt al-Arab during the later Pahlavi period, and continue to do so since the 1979 Iranian Revolution.

The Shatt al-Arab is formed by the confluence of the Tigris and Euphrates rivers at Al-Qurnah, and flows into the Persian Gulf south of the city of Al-Faw. It receives the Karun at Khorramshahr.

The Shatt al-Arab originally extended to the Ur Schatt river system that fed the Pleistocene/Holocene Arabian Gulf Oasis, a system of linked lakes and flood plains that stretched to the Strait of Hormuz and emptied into the Gulf of Oman. This system flooded in the period 12,000 - 7,000 BCE to form the present-day Persian Gulf.

Dispute over the river occurred during the Ottoman-Safavid era, prior to the establishment of an independent Iraq in the 20th century. In the early 16th century, the Iranian Safavids gained most of what is present-day Iraq, including Shatt al-Arab. They later lost these territories to the expanding Ottomans following the Peace of Amasya (1555).