Jewish ethnic divisions refer to many distinctive communities within the world's ethnically Jewish population. Although considered a self-identifying ethnicity, 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. As long ago as Biblical times, cultural and linguistic differences between Jewish communities, even within the area of Ancient Israel and Judea, are observed both within the Bible and archeological remains. In more recent human history, an array of Jewish communities were established by Jewish settlers in various places around the Old World, often at great distances from one another, resulting in significant and often long-term isolation from each other. 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. Historical background Ancient Israel and Judah 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