Lower Mesopotamia Lower Mesopotamia Lower Mesopotamia is a historical region of Iraq. Also known as the Sawad and al-'Irāq al-'Arabi ("Arabian Irāq") in the Middle Ages. Lower Mesopotamia was home to ancient Sumerian and Babylonian civilisations. An alluvial plain begins north of Baghdad and extends to the Persian Gulf. Here the Tigris and Euphrates rivers lie above the level of the plain in many places, and the whole area is a river delta interlaced by the channels of the two rivers and by irrigation canals. Intermittent lakes, fed by the rivers in flood, also characterize southeastern Iraq. A fairly large area ()
History of Mesopotamia the Roman Empire. Christianity as well as Mandeism entered Mesopotamia from the 1st to 3rd centuries AD, and flourished, particularly in Assyria (Assuristan in Sassanid Persian), which became the center of the Assyrian Church of the East and a flourishing Syriac Christian tradition which remains to this day. A number of Neo-Assyrian kingdoms arose, in particular Adiabene. The Sassanid Empire and Byzantine Mesopotamia finally fell to the Rashidun army under Khalid ibn al-Walid in the 630s. After the Arab-Islamic conquest of the mid-7th century AD, Mesopotamia saw an influx of non native Arabs and later also Turkic peoples. The city