Geography of Mesopotamia parts of Syria but also almost all of Iraq and southeastern Turkey. The neighboring steppes to the west of the Euphrates and the western part of the Zagros Mountains are also often included under the wider term Mesopotamia. A further distinction is usually made between Upper or Northern Mesopotamia and Lower or Southern Mesopotamia. Upper Mesopotamia, also known as the Jazirah, is the area between the Euphrates and the Tigris from their sources down to Baghdad. Lower Mesopotamia is the area from Baghdad to the Persian Gulf. In modern scientific usage, the term Mesopotamia often also has a chronological connotation.
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