Assyriology (from Greek Ἀσσυρίᾱ, Assyriā; and -λογία, -logia) is the archaeological, historical, and linguistic study of not just Assyria, but the entirety of ancient Mesopotamia (a region encompassing what is today modern Iraq, north eastern Syria, south eastern Turkey, and north western and south western Iran) and of related cultures that used cuneiform writing. The field covers Sumer, the early Sumero-Akkadian city-states, the Akkadian Empire, Ebla, the Akkadian and Imperial Aramaic speaking states of Assyria, Babylonia and the Sealand Dynasty, the migrant foreign dynasties of southern Mesopotamia, including; the Gutians, Amorites, Kassites, Arameans, Suteans and Chaldeans, and to some degree post-imperial Achaemenid Assyria, Athura, Seleucid Syria, Assyria (Roman province), and Assuristan, together with later Neo-Assyrian states such as Adiabene, Osroene, Hatra, Beth Nuhadra and Beth Garmai, up until the Arab invasion and Islamic conquest of the mid 7th century AD. Some Assyriologists also write on the further Assyrian continuity of the Assyrian people into the present day.