The site is located close to some other flourishing cities of the time. Hamoukar is about 50 km away to the southeast. Tell Brak is about 50 km away to the southwest, and also in the Khabur River basin. Tell Mozan is about 50 km to the west. Leilan, Brak and Urkesh were particularly prominent during the Akkadian period.
History
The city originated around 5000 BC as a small farming village and grew to be a large city ca. 2600 BC, three hundred years before the Akkadian Empire. A 3-foot layer of sediment at Tell Leilan containing no evidence of human habitation offered clues as to the cause of the demise of the Akkadian imperial city; analysis indicated that at around 2200 BC, a three-century drought was severe enough to affect agriculture and settlement.
Shubat-Enlil
The conquest of the region by Shamshi-Adad I of Assyria revived the abandoned site of Tell Leilan. Shamshi-Adad saw the great potential in the rich agricultural production of the region and made it the capital city of his empire. He renamed it from Shehna to Shubat-Enlil, or Šubat-Enlil, meaning "the residence of the god Enlil" in the Akkadian language. In the city a royal palace was built and a temple acropolis to which a straight paved street led from the city gate. There was also a planned residential area and the entire city was enclosed by a wall. The city size was about. Shubat-Enlil may have had a population of 20,000 people at its peak. After the death of Shamsh-Adad, the city became the capital of Apum and prospered until king Samsu-iluna of Babylon sacked it in 1726 BC in an attempt to maintain Babylonia's failing influence over Assyria. The Babylonians were defeated driven out of Assyria by the Assyrian king Adasi, however Shubat-Enlil was never reoccupied and the Assyrian capital was transferred to its traditional home in Aššur.
Archaeology
Beginning in 1979 the mound of Tell Leilan was excavated by a team of archaeologists from Yale University, led by Harvey Weiss. The dig ended in 2008. Among many important discoveries at Tell Leilan is an archive of 1100 cuneiformclay tablets maintained by the rulers of the city. These tablets date to the eighteenth century BC and record the dealings with other Mesopotamian states and how the city administration worked. Finds from the excavations at Tell Leilan are on display in the Deir ez-Zor Museum.