Question: "What was the Sanhedrin?"
Answer: The term Sanhedrin is from a Greek word that means “assembly” or “council” and dates from the Hellenistic period, but the concept is one that goes back to the Bible. In the Torah, God commands Moses: “bring me seventy of Israel's elders who are known to you as leaders and officials among the people. Have them come to the Tent of Meeting, that they may stand there with you" (Numbers 11:16). Also, in the sixteenth chapter of Deuteronomy, we read in verse 18, “You shall appoint for yourselves judges and officers in all your towns which the Lord your God is giving you, according to your tribes and they shall judge the people with righteous judgment.” The land was divided up among the tribes, and in those areas where tribes had their presence, there were towns and villages, and in every town and every village there was to be a court. If there were 120 men as heads of families, they had a local court there called a Sanhedrin. In smaller towns where there were not 120 men as heads of families, there were either three judges, if the town was very small, or seven judges who sat as a court, both judge and jury, in all legal matters.
The Great Sanhedrin was the supreme court of ancient Israel, made up of 70 men and the high priest. In the Second Temple period, the Great Sanhedrin met in the Temple in Jerusalem. The court convened every day except festivals and on the Sabbath. The Sanhedrin as a body claimed powers that lesser Jewish courts did not have. As such, they were the only ones who could try the king or extend the boundaries of the Temple and Jerusalem, and were the ones to whom all questions of law were finally put. The last binding decision of the Sanhedrin was in 358, when the Hebrew calendar was adopted. The Sanhedrin was dissolved after continued persecution by the Roman Empire. Over the centuries, there have been attempts to revive the institution, such as the Grand Sanhedrin convened by Napoleon Bonaparte.
In the New Testament, the Sanhedrin is best known for their part in the series of mock trials that resulted in the crucifixion of Jesus. The Sanhedrin began with an informal examination of Jesus before Annas, the acting high priest (John 18:12-14, 19-23), followed by a formal session before the entire Sanhedrin (Matthew 26:57-68). There the decision was made to turn Jesus over to the Roman authorities to be tried and crucified.