4th-century synagogue in Capernaum.

At the beginning of the first century A.D. there were Jewish communities in towns and cities across the Roman Empire. One factor that shaped Jewish identity was the Torah or Law of Moses, which prescribed distinctive practices like circumcision, eating foods that were clean or "kosher," and refraining from work on the Sabbath day. A second factor in Jewish identity was the Temple in Jerusalem, where sacrifices were offered. In A.D. 70 the Romans destroyed Jerusalem and its Temple in an effort to suppress a Jewish revolt. Leading rabbis dealt with the loss of the Temple by emphasizing the study of the Torah, ethical behavior, and the celebration of Jewish festivals in homes. Synagogues were local centers for prayer and the study of the Torah. In the second century, Jewish traditions that had been handed down orally were put into a written form known as the Mishnah. In the third through fifth centuries leading rabbis formulated interpretations of this tradition. Together, the Mishnah and the comments of the later rabbis constitute the Talmud, the core collection of teachings that would be essential to the Judaism of the medieval period and down to the present.