Dilmun (sometimes transliterated Telmun) is a land mentioned by Mesopotamian Civilizations as a trade partner, source of raw material, copper, and entrepot of the Mesopotamia and the Indus Valley Civilization trade route. Although the exact location of Dilmun is unclear, it might be associated with the islands of Bahrain, Eastern Province, Qatar, Oman and nearby Iranian coast in the Persian Gulf.
Dilmun appears first in Sumerian cuneiform clay tablets dated to the end of fourth millennium BC, found in the temple of goddess Inanna, in the city of Uruk. The adjective Dilmun is used to describe a type of axe and one specific official; in addition there are lists of rations of wool issued to people connected with Dilmun.
Dilmun was mentioned in two letters dated to the reign of Burnaburiash (c. 1370 BC) recovered from Nippur, during the Kassite dynasty of Babylon. These letters were from a provincial official in Dilmun to his superiors in Mesopotamia. The names referred to are Akkadian. These letters and other documents, hint at administrative relationship between Dilmun and Babylon at that time. Following the collapse of the Kassite dynasty, Mesopotamian documents are silent on Dilmun except Assyrian inscriptions dated to 1250 BC which proclaimed the Assyrian king to be king of Dilmun and Meluhha, as well as Lower Sea and Upper Sea. Assyrian inscriptions recorded tribute from Dilmun. There are other Assyrian inscriptions during the first millennium BC indicating Assyrian sovereignty over Dilmun. One of the early sites discovered in Bahrain suggests that Sennacherib, king of Assyria (707–681 BC), attacked northeast Arabia and captured the Bahrainian islands. The final mention of Dilmun came during the Neo-Babylonian dynasty. Neo-Babylonian administrative records, dated 567 BC, stated that Dilmun was controlled by Babylon king. The name of Dilmun fell from use after the collapse of Neo-Babylon in 538 BC
There is both literary and archaeological evidence of trade between Ancient Mesopotamia and the Indus Valley civilization (probably correctly identified with the land called Meluhha in Akkadian). Impressions of clay seals from the Indus Valley city of Harappa were evidently used to seal bundles of merchandise, as clay seal impressions with cord or sack marks on the reverse side testify. A number of these Indus Valley seals have turned up at Ur and other Mesopotamian sites. The "Persian Gulf" types of circular, stamped (rather than rolled) seals known from Dilmun, that appear at Lothal in Gujarat, India, and Failaka, as well as in Mesopotamia, are convincing corroboration of the long-distance sea trade. What the commerce consisted of is less sure: timber and precious woods, ivory, lapis lazuli, gold, and luxury goods such as carnelian and glazed stone beads, pearls from the Persian Gulf, shell and bone inlays, were among the goods sent to Mesopotamia in exchange for silver, tin, woolen textiles, olive oil and grains. Copper ingots from Oman and bitumen which occurred naturally in Mesopotamia may have been exchanged for cotton textiles and domestic fowl, major products of the Indus region that are not native to Mesopotamia—all these have been instanced. The importance of this trade is shown by the fact that the weights and measures used at Dilmun were in fact identical to those used by the Indus, and were not those used in Southern Mesopotamia.
Mesopotamian trade documents, lists of goods, and official inscriptions mentioning Meluhha supplement Harappan seals and archaeological finds. Literary references to Meluhhan trade date from the Akkadian, the Third Dynasty of Ur, and Isin-Larsa Periods (c. 2350–1800 BC), but the trade probably started in the Early Dynastic Period (c. 2600 BC). Some Meluhhan vessels may have sailed directly to Mesopotamian ports, but by the Isin-Larsa Period, Dilmun monopolized the trade. The Bahrain National Museum assesses that its "Golden Age" lasted ca. 2200-1600 BC.
Dilmun, sometimes described as "the place where the sun rises" and "the Land of the Living", is the scene of some versions of the Sumerian creation myth, and the place where the deified Sumerian hero of the flood, Utnapishtim (Ziusudra), was taken by the gods to live forever.
Dilmun is also described in the epic story of Enki and Ninhursag as the site at which the Creation occurred. Ninlil, the Sumerian goddess of air and south wind had her home in Dilmun. It is also featured in the Epic of Gilgamesh, and has been speculated to be the true location of the Garden of Eden.
However, in the early epic "Enmerkar and the Lord of Aratta", the main events, which center on Enmerkar's construction of the ziggurats in Uruk and Eridu, are described as taking place in a world "before Dilmun had yet been settled".
To date (2008) archaeology has failed to find a site in existence from 3300 B.C.(Uruk IV) to 556 B.C.(Neo-Babylonian Era) when Dilmun (Telmun) appears in texts. Despite the scholarly consensus that Dilmun encompasses three locations: (1) the eastern littoral of Arabia from the vicinity of modern Kuwait to Bahrain; (2) the island of Bahrain; (3) the island of Failaka east of Kuwait, the earliest known site is Qal'at al-Bahrain which is dated no earlier than circa 2200 B.C. according to Flemming Hojlund. Failaka was settled after 2000 B.C. following a drop in sea level according to Daniel Potts and Harriet Crawford. No settlements exist in the Arabian littoral 3300-2000 B.C. according to Hojlund. Thus, despite Dilmun's appearance in ancient texts dating from 3300-2300 B.C. archaeologists have failed to find a site for Dilmun dating to this period. Hymns regarding the Sumerian god Enki of Eridu in Sumer speak of his assaulting and deflowering Dilmun's maidens as they stand by a river bank, he reaching out of nearby marsh to clasp them to his bosom. Of Bahrain, Failaka, and the eastern littoral of Arabia, none possess marshes and a riverbank. Dilmun, furthermore, is said to lie "in the east where the sun rises," a situation that does not apply to the eastern Arabian littoral, Failaka or Bahrain, all of which lie south of Sumer and Eridu.
Howard-Carter (1987)  realizing that these three locations possess no archaeological evidence of a settlement dating 3300-2300 B.C., has proposed that Dilmun of this era might be a still unidentified tell near the Shat al-Arab between modern-day Qurnah and Basra in modern day Iraq. In favor of Howard-Carter's proposal, she noted that this area does lie to the east of Sumer ("where the sun rises"), and the riverbank where Dilmun's maidens would have been accosted aligns with the Shat al-Arab which is in the midst of marshes. The "mouth of the rivers" where Dilmun was said to lie is for her the union of the Tigris and Euphrates at Qurnah.