The history of Diaspora goes back to the 8th Century B.C. when the people of Judah in northern Palestine were taken to captivity in Babylon on the River Euphrates in modern Iraq. When the exile ended after about 200 years, a great number of their descendants remained behind and formed a community, or diaspora, which continued to be important until the middle of the 11th Century.
The next great diaspora period occurred after the death of Alexander the Great in 323 B.C. when attempts by his successors to impose Greek authority on Jewish customs in Palestine led to thousands of Jews choosing exile. This period saw the formation of the great diaspora in Alexandria, Egypt. Here in the first century B.C. more than 40% of the population were Jews who had learned to combine Greek ideas with their own to produce a flourishing culture.
But the biggest dispersal from Palestine took place under the Roman Empire, especially after A.D. 70 when the army of Titus, later Roman emperor, crushed a nationalist revolt and destroyed the temple in Jerusalem. Although financial help from exiled patriots continued, Palestine gradually ceased to be a Jewish state. In the following centuries, the "scattering" spread throughout the world.
In 1939 the estimated number of Jews in the world was 16 million of whom about 475,000 were in Palestine. Horror and pity aroused by the systematic destruction of Jews by Nazi Germany led indirectly to the creation of the State of Israel in 1948.