Shatt al-Arab in the context of "Upper Mesopotamia"

Eastern Arabia, also known as Greater Bahrain or Bahrain Region (Arabic: ٱلْبَحْرَيْن, romanized: Al-Baḥrayn), is a historical region encompassing the eastern part of the Arabian Peninsula stretching from Basra to Khasab along the coast of the Persian Gulf. It includes parts of the modern-day states of Bahrain, Iraq (Basra Governorate), Kuwait, Oman, Qatar, Saudi Arabia (Eastern Province), and the United Arab Emirates. The entire coastal strip of Eastern Arabia was known as "Bahrain" for a millennium.

Until very recently, the whole of Eastern Arabia, from the Shatt al-Arab to the mountains of Oman, was a place where people moved around, settled and married unconcerned by national borders. The people of Eastern Arabia shared a culture based on the sea, as seafaring peoples.

The Tigris–Euphrates river system is a large river system in West Asia that flows into the Persian Gulf. Its primary rivers are the Tigris and Euphrates, along with smaller tributaries.

From their sources and upper courses in the Armenian highlands of eastern Turkey, being Lake Hazar for the Tigris and Karasu along with the Murat River for the Euphrates, the two rivers descend through valleys and gorges to the uplands of Syria and northern Iraq and then to the alluvial plain of central Iraq. Other tributaries join the Tigris from sources in the Zagros Mountains to the east. The rivers flow in a south-easterly direction through the central plain and combine at Al-Qurnah to form the Shatt al-Arab and discharge into the Persian Gulf. The rivers and their tributaries drain an area of 879,790 square kilometres (339,690 sq mi), including almost the entire area of Iraq as well as portions of Turkey, Syria, Iran and Kuwait.

The Euphrates (/juːˈfreɪtiːz/ yoo-FRAY-teez; see below) is the longest and one of the most historically important rivers of West Asia. Together with the Tigris, it is one of the two defining rivers of Mesopotamia (lit. 'the land between the rivers'). Originating in Turkey, the Euphrates flows through Syria and Iraq to join the Tigris in the Shatt al-Arab in Iraq, which empties into the Persian Gulf.

The Euphrates is the fifteenth-longest river in Asia and the longest in West Asia, at about 2,780 km (1,730 mi), with a drainage area of 440,000 km (170,000 sq mi) that covers six countries.

The Persian Gulf, sometimes called the Arabian Gulf, is a mediterranean sea in West Asia. The body of water is an extension of the Arabian Sea and the larger Indian Ocean located between Iran and the Arabian Peninsula. It is connected to the Gulf of Oman in the east by the Strait of Hormuz. The river delta of the Shatt al-Arab forms the northwest shoreline.

The Persian Gulf has many fishing grounds, extensive reefs (mostly rocky, but also coral), and abundant pearl oysters; however, its ecology has been damaged by industrialization and oil spills.

The Iran–Iraq border runs for 1,599 km (994 mi) from the tripoint with Turkey in the north down to the Shatt al-Arab (known as Arvand Rud in Iran) waterway and out to the Persian Gulf in the south. Although the boundary was first determined in 1639, certain disputes continue, particularly surrounding navigation on the Shatt al-Arab.

Basra (Arabic: ٱلْبَصْرَة, romanized: al-Baṣrah) or Basrah is a port city in southern Iraq. It is the capital of the eponymous Basra Governorate, as well as the third largest city in Iraq overall, behind Baghdad and Mosul. Located near the Iran–Iraq border, the city is situated along the banks of the Shatt al-Arab that empties into the Persian Gulf. It is consistently one of the hottest cities in Iraq, with summer temperatures regularly exceeding 50 °C (122 °F).

Built in 636 as a military camp, Basra played an important role as a regional hub of knowledge, trade and commerce during the Islamic Golden Age and is home to the first mosque built outside the Arabian Peninsula. It was a center of the slave trade in Mesopotamia, until the Zanj rebellion in 871. Historically, Basra is one of the ports from which the fictional Sinbad the Sailor embarked on his journeys. It has experienced numerous ruling shifts. In 1258, the city was sacked by the Mongols. Basra came under Portuguese control in 1526 and later fell under the control of the Ottomans as part of the Basra Eyalet, one of the provinces comprising Ottoman Iraq. During World War I, British forces captured Basra in 1914. It was incorporated into Mandatory Iraq, under the framework Mandate for Mesopotamia after 1921, which later became the independent Kingdom of Iraq in 1932.

Al-Qurnah (Kurnah or Qurna, meaning connection/joint in Arabic) is a town in southern Iraq about 74 km northwest of Basra, that lies within the conglomeration of Nahairat. Qurna is located at the confluence point of the Tigris and Euphrates rivers to form the Shatt al-Arab waterway. Local folklore holds Qurnah to have been the original site of biblical paradise, the Garden of Eden, and location of the Tree of Knowledge.