In Biblical times, the court of Israel was dominated by two forms of large courts: Sanhedrin (Hebrew: סנהדרין) .The smaller courts, known as “Small Sanhedrins,” were composed of 23 sages each and were located throughout the land of Israel. The large court, the "Great Sanhedrin", composed of 71 of the greatest sages of Israel.
The Great Sanhedrin dealt with religious and ritualistic Temple matters, criminal matters appertaining to the secular court, proceedings in connection with the discovery of a corpse, trials of adulterous wives, tithes, preparation of Torah Scrolls for the king and the Temple, drawing up the calendar and the solving of difficulties relating to ritual law.
The idea of a Jewish tribunal originated with Jethro, who advised Moses, , to choose a group of elderly men to help him judge the people (Exodus 18:17-26). G-d ordered Moses to choose 70 men from Israel and bring them before the Tabernacle ,where they would receive enlightenment to judge the people who violated Jewish law. This tribunal became known as Sanhedrin.
This tribunal had little influence until the Jewish exile under the Persians, when it started to effectively judge the difficult questions of the Jewish people.