History
The Euphrates and its tributary the Khabur made the east a corridor between Mesopotamia and the Mediterranean from the earliest times. Mari, on the river near today's Iraqi border, was a rich city-state in the third and second millennia BC until Hammurabi of Babylon destroyed it in the 18th century BC; its palace archive of tablets is one of the great sources for the period. In the Jazira, tells such as Tell Brak, Tell Halaf and Tell Leilan mark early cities and the Hurrian and Aramaean kingdoms that followed.
Dura-Europos was founded by the Seleucids around 300 BC, became a Roman garrison town facing Parthia and then Persia, and was abandoned after a Sasanian siege in the 250s, preserving its buildings under sand. The Byzantines fortified Resafa, the Umayyads built palaces in the steppe, and the Abbasid caliph al-Mansur founded al-Rafiqa beside Raqqa, where Harun al-Rashid kept his court in the 790s and 800s. Mongol invasions ruined the valley, and for centuries it belonged mostly to Bedouin tribes.
Under late Ottoman rule Deir ez-Zor became the centre of a district, and in 1915–16 its desert became the end point and killing ground of the Armenian deportations. The French mandate brought Assyrian refugees to the Khabur in the 1930s and the Tabqa Dam created Lake Assad in the 1970s. In the civil war ISIS made Raqqa its capital in 2014, and Kurdish-led forces backed by a US-led coalition took the city in 2017, leaving it largely destroyed; ISIS lost its last territory at Baghuz, near the Iraqi border, in 2019.
