640 MOHAMMEDAN ARABS TOOK OVER EGYPT
Jews who had previously lived there gradually returned.
641 HERACLIUS DIED IN CONSTANTINOPLE (Byzantine Empire)
Despite the constant suppression of Judaism, many Jews had remained in Constantinople and they became the target of anti-Jewish riots.
641 SOLIN (near Split, present day Croatia)
After an attack by the Mongolian Avars, the Jewish community which had existed for 300 years was destroyed.
641 THE TREATY OF ALEXANDRIA (Egypt),
With the Arab conquest of Egypt the Jews were specificity allowed to continue to live in the city. Amr ibn al-ĎAs(i) the Arab commander estimated that there were approximately 40,000 Jews in the city including many who had fled Byzantine persecutions.
642 BOSTANI OR BUSTANAI (Persia)
The first Exilarch to be recognized by Arab rulers. His birth and much of his life is surrounded by legend. As a token of appreciation, Caliph Ali gave him the daughter of the Persian king Yazdegerd III for a slave. Eventually Bustanai married her.