Human habitation of the Qatar Peninsula dates as far back as 50,000 years when small groups of inhabitants built coastal encampments, settlements, and sites for working flint that were dated to be from the Neolithic era, according to archaeological evidence.
Recent discoveries in Wadi Debay’an, a site located a few kilometers south of Zubara, indicate human presence from 7,500 years ago. Amongst the findings were a wall built of stone, possibly used as a fish trap. Discovery of a 6th millennium BC site at Shagra, in southeastern Qatar revealed the key role the sea (the Persian Gulf) played in the lives of Shagra’s inhabitants. Excavations at Al Khor in northeastern Qatar, Bir Zekrit and Ras Abaruk, and the discovery there of pottery, flint, flint-scraper tools, and painted ceramic vessels indicates Qatar’s connection with the Al-Ubaid civilisation, which flourished in the land between the Tigris and the Euphrates rivers in present-day Iraq during the period of 5th–4th millennium BC. It is thought that Mesopotamian fisherman working the rich fishing banks off the Arabian coast visited local settlements, bringing pottery with them and exchanging it for fresh meat in an improvised barter-based trade system. The first potsherds of the Ubaid Mesopotamia were found by a Danish expedition in Al Da'asa in 1961, but not identified until later. A second expedition was held in 1973–74 led by Beatrice De Cardi. Contact between the people of Mesopotamia and the eastern Arabian coast (including Qatar) continued over centuries.
In the early 3rd millennium, Sumerians settled on Tarut Island, off the Saudi coast, approximately 100 kilometers north-west of Qatar. Later, from 2450–1700 BC, Dilmun, a peaceful trading civilization, was centered in Bahrain. Evidence that Qatar was part of the complex trading network is found from the presence of Barbar pottery, a product of the Dilmun civilization, in Ras Abrouk.