In 66 C.E., the Jews of ancient Israel rebelled against their Roman overlords and hastily completed the city wall as a part of their defense system. The wall did not hold, however; the Roman army breached it, going on to destroy Jerusalem and the Temple, the focus of ancient sacrificial worship. The Jews were exiled from the city and were forced to devise an alternative form of worship, based on prayer in the synagogue and the study of the sacred tests.