The Oral Torah and its Times

Around this time, Ezra Hasofer started the Knesset Gedolah, which had 120 judges and was the main Rabbinic lawmaking body at the time. It later became the Sanhedrin, which had 7 judges and was the equivalent of today's Congress and Supreme Court. In order to be inducted into the Sanhedrin, one had to pass a test and be given סמיכה, which was when an existing Rabbi placed his hands on the new Rabbi's head as a metaphoric transfer of power. Smaller courts that branched from the Knesset Gedolah and Sanhedrin had at least 3 judges and were located throughout Israel.

The Mishnah was created in Israel and compiled by Rabbi Akivah, Rabbi Meir and eventually completed by Rabbi Yehudah Hanasi. It is a collection of the discussions of the Tana'im (Sages of the time, also a term for those who memorized the oral Torah before it was written down) through 200 CE. It was created to clarify ambiguous portions of the Tanach and to help apply the laws to different times.

*year is an approximation
The Gemarah is a collection of the discussions of the Amora'im (Sages of the time) that took place after about 200 CE. It clarifies and debates sections of the Mishnah. (See Mishnah)

*year is an approximation; historians believe that this gemarah was completed between the years 500 and 600 CE

See the Jerusalem Gemarah for a description of the Gemarah

The Babylonians destroyed the 1st Holy Temple in Jerusalem and exlied the Jews to Babylonia.

After the Babylonians were conquered by the Persians, the Persians allowed Jews to return to Israel from exile.

After the destruction of the Temple by the Romans, Yavneh became the new center of Judaism. The Sanhedrin and its Sages became the leaders of the Jewish community.

Ezra Hasofer was a scribe who acted as the religious leader for Jews returning from exile. He worked with Nechemya to help rebuild the Jewish community. He helped to institute individual synagogues, rebuild the Holy Temple, put the Torah in its final form and create the Knesset Gedolah.

After the destruction of the Second temple, rabbi Yohanan helped to reestablish a Jewish community in Yavneh. He helped the Sanhedrin (which he was the leader of) take judicial and religious control over the Jews in Israel.