By the end of the 4th century, following Emperor Constantine's adoption of Christianity (313) and the founding of the Byzantine Empire, the Land of Israel had become a predominantly Christian country. Churches were built on Christian holy sites in Jerusalem, Bethlehem and Galilee, and monasteries were established in many parts of the country. The Jews were deprived of their former relative autonomy, as well as of their right to hold public positions, and were forbidden to enter Jerusalem except on one day of the year (Tisha b'Av - ninth of Av) to mourn the destruction of the Temple.
The Persian invasion of 614 led by Heraclius was welcomed and aided by the Jews, who were inspired by messianic hopes of deliverance. In gratitude for their help, they were granted the administration of Jerusalem, an interlude which lasted about three years. Subsequently, the Byzantine army regained the city (629) and again expelled its Jewish population.