Prior to the late 19th cent. there had been very little emigration from the Middle East, whereas today there are more Christians from the Syriac (and other Middle Eastern) Churches living in the Diaspora than remain in the homelands. The two main causes of this massive demographic change are 1. the massacres in Syria and Lebanon of 1860, and especially those in Eastern Turkey of 1895/6 and of 1915 (see Sayfo) and following years; and 2. the continuing unsettled political situation, involving wars and civil strife, in many countries of the Middle East, where certain events in particular have given rise to renewed waves of emigration, notably in 1933 after the end of the British Mandate in Iraq (1932), involving the Assyrians; the creation of the state of Israel in 1948 and the three subsequent wars (1956, 1967, 1973), involving the Syr. Orth. in Palestine; the Lebanese civil war (1975–1990), involving the Maronites and other Syr. communities in Lebanon; the Turkish-Kurdish conflict in Eastern Turkey, involving mainly the Syr. Orth.; the Iraqi-Kurdish conflict, followed by the Iraq-Iran war (1980–88), the Gulf war (1990–1), and the invasion of Iraq (2003), involving the Chaldeans, Assyrians, Syr. Catholic, and Syr. Orth. In all these upheavals displacement and emigration has also been to other countries within the Middle East (or even within the same country), as well as to countries outside it (with or without refugee status). A further cause of emigration has been the lack of educational or employment opportunities in the countries of origin; this had already led to the earliest immigration to the United States (Chicago, New Britain, CT) from north-west Iran (Urmia region) in the late 19th cent.

The massacres of 1895/6 and 1915–18 led to large scale emigration, both within the Middle East (mainly to Syria, Lebanon, Palestine in the case of the Syr. Orth.; to Iraq, Iran, and the Caucasus [and thence, to Russia] in the case of the Chaldeans and Assyrians) and to the West, above all at this stage to the Americas, both North and South. The flight of Assyrians from Iraq in 1933 resulted in new settlements in eastern Syria, while others emigrated to Britain and especially the United States. The Americas were also the goal of most of those emigrating after the creation of Israel, and it has only been in the last 50 years that large numbers from all the Syr. Churches have emigrated to countries of western Europe, with a preponderance of Syr. Orth. settling in Germany (where the first priest was ordained in 1977) and Sweden, and of Chaldeans and Maronites in France. An important development in the case of the Syr. Orth. was the founding of three monasteries by the late bp. Julius Çiçek (Mor Ephrem, Netherlands, 1984; Mor Augen, Switzerland, 1999; Mor Yaʿqub da-Srug, Germany, 2000). Smaller communities from the different Syr. Churches are also found in Russia, Denmark, the Netherlands, Belgium, Switzerland, Austria, Italy, Britain, and Greece. More recently emigration on a large scale has also been to Australia. A pattern followed in many cases has been for emigrés from a particular village to settle together in their new home. Since 2003 it has been Syria, Jordan, and Turkey that have been the immediate goals of those fleeing from the dangerous situation in Iraq.

The increasing sizes of the Diaspora communities has led to the creation of new dioceses outside the Middle East, following on from the earlier establishment of church communities in the different countries. The main topic of the 16th Congress of Catholic Patriarchs of the Middle East in 2006 was emigration. The following listing of Diaspora dioceses gives some idea of the geographical spread for each of the Syr. Churches; figures for numbers, where given, are inevitably only approximate (these can vary considerably from one source to another).

Ancient Church of the East: Germany (Mainz), Western USA (Modesto, California), and Australia and New Zealand.

Assyrian Church of the East: Europe (Norsborg, Sweden); Canada (Weston, Ontario); Eastern USA (Chicago; residence of the patr. ), Western USA (Glendale, Arizona); Western California (San Jose); Australia and New Zealand (Sydney). With communities in several other countries, including Denmark, Germany, Great Britian, Greece, and Russia. Whereas some 150,000 now live in the Diaspora (ca. 90,000 in USA, and 10,000 in Australia/New Zealand), only ca. 100,000 remain in the Middle East.

Chaldean Catholic Church: USA (Southfield, Michigan; San Diego [since 2002]), with ca. 170,000 faithful; Australia and New Zealand (since 2006), with ca. 15,000. There are sizeable communities in Canada (Montreal, Toronto, Windsor), and in Europe (especially France, with communities in Paris, Lyon, and Marseille; but also Sweden, Germany, Belgium, and smaller ones in Greece, Netherlands, Denmark, and Great Britain).

Maronite Church: USA (Brooklyn, Los Angeles); Canada (Montreal); Brazil (Sao Paolo); Argentina (Buenos Aires [since 1990]); Mexico (since 1995); Australia (Strathfield, NSW); and sizeable communities in Europe, especially France. Estimates ranging between one million and two and a half million are given for Maronites in the Diaspora (a high proportion are in South America), while little over half a million remain in the Middle East.

Syrian Catholic Church: USA (Newark NJ [since 1995]) and Venezuela (since 2001); with communities in USA in Detroit, Los Angeles, San Diego, and Jacksonville (Florida). In Canada there are communities in Toronto and Montreal; in Europe, notably in Amsterdam, London, and Paris; in Australia, in Sydney. An estimated 50,000 (out of a total of ca. 100,000) live in the Diaspora.

Syrian Orthodox Church: Europe: Sweden and Scandinavia (Södertälje and Klockarvägen); Germany (Warburg); Netherlands (Glane); Belgium (Brussels); Great Britain (London); with further communities in France, Switzerland, Italy, and Austria; USA (Teaneck, New Jersey; Burbank, California); Canada (Saint Laurent, Québec); Australia and New Zealand (Lidcombe, NSW); Argentina (La Plata). Some 150,000 live in the Diaspora, while roughly the same number remain in the Middle East (by far the largest numbers are in India).

The different Indian Churches of Syr. tradition also have considerable diasporas all over the world, and several now have a North American diocese (Syro-Malabar: Chicago, since 2001; Syro-Malankara: for America and Europe, since 2005; Syrian Orthodox: Cartaret, New Jersey; Orthodox Syrian: Alma, Michigan, and Belrose, New York). There are communities in several European countries from all the Syr. Churches in India (especially Great Britain, Ireland, Germany, Switzerland, and Austria). Many from Kerala go as temporary workers to the Gulf states, in some of which churches have been built.

The above locations only cover countries where church communities have been established; for individuals from the Syr. Churches of the Middle East, the scatter is much wider, and includes countries of Africa and East Asia.

The move to secular societies where ethnic and cultural, rather than religious, identity is paramount has caused much dispute in the search for appropriate names to use (Aramaean, Assyrian, Chaldean, Assyro-Chaldean, Syriac, Suryoyo, etc.), and the issue has often proved sadly divisive, especially among the Syr. Orth. On the other hand, many new opportunities have been opened up, for the creation of cultural and other associations, and for new educational possibilities. In the 1930s when for a time it was Soviet policy to encourage minority languages, the written use of Modern Syriac (in Latin script) was encouraged; a more recent adaptation of the spoken language to western script has taken place with Turoyo in Sweden. Especially important has been the freedom to publish in western countries. This has given rise to a great many cultural magazines, often multilingual (and including both Classical and Modern Syriac), as well as the creation of television channels (such as Suryoyo SAT, Suroyo TV, Assyrian TV); it has also made it possible to publish information about the Sayfo. Another notable development has been in the creation of music groups, both church-based and secular, the latter using lyrics in both Classical and Modern Syriac; though this development had its origins in the Middle East (e.g., Qamishli in the 1960s, and rather earlier in Iran), it has been greatly developed in the Diaspora.

See Fig. 40, 41, and 42 .