Once, as Rabban Johanan ben Zakkai was coming forth from Jerusalem, Rabbi Joshua followed after him and beheld the Temple in ruins.

"Woe unto us!" Rabbi Joshua cried, "that this, the place where the iniquities of Israel were atoned for, is laid waste!"

"My son," Rabban Johanan said to him, "be not grieved; we have another atonement as effective as this. And what is it? It is acts of loving-kindness, as it is said, For I desire mercy and not sacrifice." [Hosea 6:6]

Judah Goldin, tr., The Fathers According to Rabbi Nathan (Yale University Press, 1955)

Jerusalem and the Temple served as the political and religious center of Jewish life for almost 1,000 years. The destruction of the Temple in 70 CE was a catastrophe, affecting not only Jews in the Land of Israel, but also large numbers already living in the Diaspora. Fortunately for the survival of Judaism, however, the Pharisaic belief that religious authority should rest with rabbis (teachers) rather than with the Temple priesthood had already firmly taken hold. Under the leadership of Johanan ben Zakkai, a group of rabbis assembled in Jabneh, a small town south of Jerusalem, where they established a synagogue and rabbinical academy. Over time, individual synagogues assumed a heightened importance throughout the Diaspora as places of prayer, learning, and social activity. Religious authority shifted to the new rabbinical institutions that were developing in Palestine and Babylonia.

The Pharisees conceived of Torah, or divine law, as composed of two dimensions: a written law and an oral law, which interpreted, refined, and elaborated upon the written text. This concept reinforced the pliability of Judaism’s sacred tradition, allowing it to adjust and modify itself to the needs of Jewish life in subsequent centuries. In about 200 CE, a selection of oral law was compiled into the Mishnah, the work that became the foundation for the continued development of Judaism.

Economic conditions in the devastated Land of Israel led many Jews to settle elsewhere in the Roman Empire or beyond the empire’s borders, in Babylonia. The Babylonian Jewish community, established in biblical times, eventually became the largest and most influential of Diaspora Jewish settlements. It was here that the Babylonian Talmud (a compilation of the Mishnah and rabbinical commentary) was completed in around 500 CE.

In the Roman Empire, Christianity had grown from a Jewish sect to a separate religion whose differences with Judaism had become irreconcilable by the end of the 1st century CE. The emperor Constantine began to favor Christianity in 312 CE, and by the end of the 4th century CE, the once persecuted faith had become the official religion of the Roman Empire. Jews found their civil status reduced under imperial Rome. By the beginning of the 5th century, they were subject to civil and economic restrictions that eventually served as the basis for the legal status of Jews in medieval Europe.

By 476 CE, the once mighty Roman empire had fallen victim to poor government and barbarian invasions. Centralized government deteriorated and countless petty chiefs set themselves up as lords. Government and classical culture crumbled, the old Roman roads decayed, and what later generations would call the Dark Ages settled upon Europe.
On the Arabian peninsula, Islam, the third great monotheistic religion, was born in the 7th century CE. Influenced by both Judaism and Christianity, Islam is based on divine revelation in the form of a text—in Islam’s case, the Quran. The new religion spread quickly throughout the Arab world. Less than a century after the death of the prophet Muhammad, Muslim rule extended over a vast empire stretching from Afghanistan to Spain. A cultured and sophisticated Islamic civilization flourished in the great cities of Baghdad and Cordoba. The treasures of classical Hellenistic civilization were translated into Arabic by Muslim scholars. During this period of Islam’s flowering, the Jews in Muslim lands constituted the majority of world Jewry and shared in the vigorous cultural awakening.