Jewish ethnic divisions

Jewish ethnic divisions refer to many distinctive communities within the world's Jewish population. Although "Jewish" is considered an ethnicity itself, there are distinct ethnic subdivisions among Jews, most of which are primarily the result of geographic branching from an originating Israelite population, mixing with local communities, and subsequent independent evolutions.

During the millennia of the Jewish diaspora, the communities would develop under the influence of their local environments; political, cultural, natural and demographic. Today, the manifestation of these differences among the Jews can be observed in Jewish cultural expressions of each community, including Jewish linguistic diversity, culinary preferences, liturgical practices, religious interpretations, and degrees and sources of genetic admixture.

The full extent of the cultural, linguistic, religious or other differences among the Israelites in antiquity is unknown. Following the defeat of the Kingdom of Israel in the 720s BCE and the Kingdom of Judah in 586 BCE, the Jewish people became dispersed throughout much of the Middle East and Africa, especially in Egypt and North Africa to the west, as well as in Yemen to the south, and in Mesopotamia to the east. The Jewish population in ancient Israel was severely reduced by the Jewish–Roman wars and by the later hostile policies of the Christian emperors against non-Christians, but the Jews always retained a presence in the Levant. Paul Johnson writes of this time: "Wherever towns survived, or urban communities sprang up, Jews would sooner or later establish themselves. The near-destruction of Palestinian Jewry in the second century turned the survivors of Jewish rural communities into marginal town-dwellers. After the Arab conquest in the seventh century, the large Jewish agricultural communities in Babylonia were progressively wrecked by high taxation, so that there too the Jews drifted into towns and became craftsmen, tradesmen, and dealers. Everywhere these urban Jews, the vast majority literate and numerate, managed to settle, unless penal laws or physical violence made it impossible."

Jewish communities continued to exist in Palestine in relatively small numbers: during the early Byzantine 6th century there were 43 communities; during the Islamic period and the intervening Crusades there were 50 (including Jerusalem, Tiberias, Ramleh, Ashkelon, Caesarea, and Gaza); and during the early Ottoman 14th century there were 30 (including Haifa, Shechem, Hebron, Ramleh, Jaffa, Gaza, Jerusalem, and Safed). The majority of the Jewish population during the High Middle Ages lived in Iberia (what is now Spain and Portugal) and in the region of Mesopotamia and Persia (what is now Iraq and Iran), the former known as the Sefardim and the latter known as the Mizrahim. A substantial population existed also in central Europe, the so-called Ashkenazim. Following the expulsion of Sephardim from Iberia during the 15th century, a mass migration into the Ottoman Empire swelled the size of many eastern communities including those in Palestine; the town of Safed reached 30,000 Jews by end of the 16th century. The 16th century saw many Ashkenazi Kabbalists drawn to the mystical aura and teachings of the Jewish holy city. Johnson notes that in the Arab-Muslim territories, which included most of Spain, all of North Africa, and the Near East south of Anatolia in the Middle Ages, the Jewish condition was easier as a rule, than it was in Europe.

Over the centuries following the Crusades and Inquisition, Jews from around the world began emigrating in increasing numbers. Upon arrival, these Jews adopted the customs of the Mizrahi and Sephardi communities into which they moved.^{[citation needed]}

Following the failure of the second revolt against the Romans and the exile, Jewish communities could be found in nearly every notable center throughout the Roman Empire, as well as scattered communities found in centers beyond the Empire's borders in northern Europe, in eastern Europe, in southwestern Asia, and in Africa. Farther to the east along trade routes, Jewish communities could be found throughout Persia and in empires even farther east including in India and China. In the Early Middle Ages of the 6th to 11th centuries, the Radhanites traded along the overland routes between Europe and Asia earlier established by the Romans, dominated trade between the Christian and the Islamic worlds, and used a trade network that covered most areas of Jewish settlement.^{[citation needed]}

In the middle Byzantine period, the khan of Khazaria in the northern Caucasus and his court converted to Judaism, partly in order to maintain neutrality between Christian Byzantium and the Islamic world. This event forms the framework for Yehuda Halevi's work The Kuzari (c.1140), but how much the traces of Judaism within this group survived the collapse of the Khazar empire is a matter of scholarly debate. Arthur Koestler, in his book The Thirteenth Tribe (1976), and more recently Shlomo Sand in his book The Invention of the Jewish People (2008) theorized that East-European Jews are more ethnically Khazar than they are Semitic. Genetic studies have not supported this theory.

In western Europe, following the collapse of the Western Roman Empire in 476, and especially after the re-orientation of trade caused by the Moorish conquest of Iberia in the early 8th century, communications between the Jewish communities in northern parts of the former western empire became sporadic. At the same time, rule under Islam, even with dhimmi status, resulted in freer trade and communications within the Muslim world, and the communities in Iberia remained in frequent contact with Jewry in North Africa and the Middle East, but communities further afield, in central and south Asia and central Africa, remained more isolated, and continued to develop their own unique traditions. For the Sephardim in Spain, it resulted in a "Hebrew Golden Age" in the 10th to 12th centuries. The 1492 expulsion from Spain by the Catholic Monarchs however, made the Sephardic Jews hide and disperse to France, Italy, England, the Netherlands, Scandinavia, parts of what is now northwestern Germany, and to other existing communities in Christian Europe, as well as to those within the Ottoman Empire, to the Maghreb in North Africa and smaller numbers to other areas of the Middle East, and eventually to the Americas in the early 17th century.