Editing History of Iraq (section)

===Sassanid Empire===
{{Main|Asoristan}}
[[File:The Sasanian Empire at its apex under Khosrow II.svg|thumb|The [[Sasanian Empire]] at its greatest extent in c. 620 under [[Khosrow II]]]]
In the 3rd century AD, the Parthians were in turn succeeded by the [[Sassanid dynasty]], which ruled Mesopotamia until the 7th-century Islamic invasion. The Sassanids conquered the independent states of [[Adiabene]], [[Osroene]], [[Hatra]], and finally [[Assur]] during the 3rd century. In the mid-6th century, the Persian Empire under the Sassanid dynasty was divided by [[Khosrow I]] into four quarters, of which the western one, called ''Khvārvarān'', included most of modern Iraq, and was subdivided into the provinces of ''Mishān'', [[Asuristān]] ([[Assyria]]), [[Adiabene]], and Lower Media. The term Iraq is widely used in the medieval Arabic sources for the area in the center and south of the modern republic as a geographic rather than a political term, implying no greater precision of boundaries than the term "Mesopotamia" or, indeed, many of the names of modern states before the 20th century.

There was a substantial influx of [[Arabs]] in the Sassanid period. [[Upper Mesopotamia]] came to be known as ''Al-Jazirah'' in Arabic (meaning "The Island" in reference to the "island" between the Tigris and Euphrates rivers), and Lower Mesopotamia came to be known as ''[[name of Iraq|ʿIrāq-i ʿArab]]'', meaning "the escarpment of the Arabs" (viz. to the south and east of "the island").<ref>possibly an Arabic folk etymology of an older toponym deriving from the name of ''[[Uruk]]'', see [[name of Iraq]].</ref>

Until 602, the desert frontier of the Persian Empire had been guarded by the Arab [[Lakhmid]] kings of [[Al-Hirah]]. In that year, [[Shahanshah]] [[Khosrow II]] Aparviz (Persian خسرو پرويز) abolished the Lakhmid kingdom and laid the frontier open to nomad incursions. Farther north, the western quarter was bounded by the Byzantine Empire. The frontier more or less followed the modern [[Syria-Iraq border]] and continued northward, passing between [[Nusaybin|Nisibis]] (modern Nusaybin) as the Sassanian frontier fortress and Dara and [[Amida (Mesopotamia)|Amida]] (modern [[Diyarbakır]]) held by the [[Byzantine Empire|Byzantines]].