Assyrian continuity is the study of continuity between the modern Assyrian people, a recognised Semitic indigenous ethnic, religious, and linguistic minority in Western Asia (particularly in Iraq, northeast Syria, southeast Turkey, northwest Iran and in the Assyrian diaspora) and the people of Ancient Mesopotamia in general and ancient Assyria in particular. Assyrian continuity and Ancient Mesopotamian heritage is a key part of the identity of the modern Assyrian people. No archaeological, genetic, linguistic, anthropological, or written historical evidence exists of the original Assyrian and Mesopotamian population being exterminated, removed, bred out, or replaced in the aftermath of the fall of the Assyrian Empire. Modern contemporary scholarship "almost unilaterally" supports Assyrian continuity, recognizing the modern Assyrians as the ethnic, historical, and genetic descendants of the East Assyrian-speaking population of Bronze Age and Iron Age Assyria specifically, and (alongside the Mandeans) of Mesopotamia in general, which were composed of both the old native Assyrian population and of neighboring settlers in the Assyrian heartland.
Due to an initial long-standing shortage of historical sources beyond the Bible and a handful of inaccurate and contradictory works by a few later classical European authors, many Western historians prior to the early 19th century believed Assyrians (and Babylonians) to have been completely annihilated, although this was never the view in the region of Mesopotamia itself or surrounding regions in West Asia, where the name of the land continued to be applied until the mid 7th century AD, and Assyrian people have continued to be referenced as such through to the present day.
European writers also often inaccurately equated Assyrians with Nestorians during the Medieval Era, a now unanimously rejected idea that lingered into the early 19th century among some western scholars, despite Assyrian conversion to Christianity preceding Nestorianism by many centuries, and Assyrians being members of churches such as the Assyrian Church of the East, Syriac Orthodox Church (and from the 17th century offshoot of the Assyrian Church, the Chaldean Catholic Church) which are doctrinally distinct from Nestorianism.
Modern Assyriology has increasingly and successfully challenged the initial Western perception; today, Assyriologists, Iranologists and historians recognize that Assyrian culture, identity, and people clearly survived the violent fall of the Neo-Assyrian Empire and endured into modern times. The last period of ancient Assyrian history is now regarded to be the long post-imperial period from the 6th century BC through to the 7th century AD when Assyria was also known as Athura, Assyria Provincia and Asoristan, during which the Akkadian language gradually went extinct by the 1st century AD, but other aspects of Assyrian culture, such as religion, traditions, and naming patterns, and the Akkadian influenced East Aramaic dialects specific to Mesopotamia survived in a reduced but highly recognizable form before giving way to specifically native forms of Eastern Rite Christianity, with the Akkadian influenced Assyrian Aramaic dialects surviving into the present day.
The gradual extinction of Akkadian and its replacement with Akkadian influenced East Aramaic does not reflect the disappearance of the original Assyrian population; Aramaic was used not only by settlers but was also adopted by native Assyrians and Babylonians, in time even becoming used by the royal administrations of Assyria and Babylonia themselves, and indeed retained by the succeeding Indo-European speaking Achaemenid Empire. In fact, the new language of the Neo-Assyrian Empire, the Imperial Aramaic, was itself a creation of the Assyrian Empire and its people, and with its retention of an Akkadian grammatical structure and Akkadian words and names, is distinct from the Western Aramaic of the Levant which gradually replaced the Canaanite languages (with the partial exception of Hebrew). In addition, Aramaic also replaced other Semitic languages such as Hebrew, Phoenician, Arabic, Edomite, Moabite, Amorite, Ugarite, Dilmunite, and Chaldean among non-Aramean peoples without prejudicing their origins and identity. Since the Aramaic language was so deeply integrated into the empire and due to the fact it was spread chiefly by Assyria, in later Demotic Egyptian, Greek, and Mishanic Hebrew texts it was referred to as the "Assyrian writing." Due to assimilation efforts encouraged by Assyrian kings, fellow Semitic Arameans, Israelites, Judeans, Phoenicians, and other non-Semitic groups such as Hittites, Hurrians, Urartians, Phrygians, Persians, and Elamites deported into the Assyrian heartland are also likely to quickly have been absorbed into the native population, self-identified, and been regarded, as Assyrians. The Assyrian population of Upper Mesopotamia was largely Christianized between the 1st and 4th centuries AD, however Mesopotamian religion enduring among Assyrians in small pockets until the late Middle Ages, a further indication of continuity. Assyrian Aramaic-language sources from the Christian period predominantly use the self-designation Suryāyā ("Syrian") alongside "Athoraya" and "Asoraya" The term Suryāyā, sometimes alternatively translated as "Syrian" or "Syriac", is generally accepted to derive from the ancient Akkadian Assūrāyu, meaning Assyrian. The academic consensus is that the modern name "Syria" originated as a shortened form of "Assyria" and applied originally only to Mesopotamian Assyria and not to the modern Levantine country of Syria.
Assyrian nationalism centered on a desire for self-determination developed near the end of the 19th century, coinciding with increasing contacts with Europeans, increasing levels of ethnic and religious persecution, along with increased expressions nationalism in other Middle Eastern groups, such as the Arabs, Armenians, Copts, Jews, Kurds, Persians, and Turks. Through the large-scale promotion of long extant terms and promotion of identities such as ʾĀthorāyā and ʾAsurāyā, Assyrian intellectuals and authors hoped to inspire the unification of the Assyrian nation, transcending long-standing religious denominational divisions between the Assyrian Church of the East, its 17th century offshoot, the Chaldean Catholic Church, the Syriac Orthodox Church, and various smaller largely Protestant denominations. This effort has been met with both support and some opposition from various religious communities; some denominations have rejected unity and promoted alternate religious identities, such as "Aramean", "Syriac", and "Chaldean". Though some religious officials and activists (particularly in the west) have promoted such identities as separate ethnic groups rather than simply religious denominational groups, they are not generally treated as such by international organizations or historians, and historically, genetically, geographically and linguistically these are all the same Assyrian people.