Preeminent successor to the Great Assembly, noted above. An assembly of the 71 greatest Jewish judges and scholars of the time. Various Sanhedrins will appear periodically over a several hundred year span. The august legislative–judicial–Halakhic body was one of the most esteemed institutions in Judaism’s entire 3,000–year history.
According to both Roman and Jewish sources, the Sanhedrin ceased prosecuting capital cases after Rome asserted control over Jerusalem/Judea c. 6 CE.
When Rome co–opted the Sanhedrin c. 6 CE, by imposing the High Priest (which Rome selected) as head of the Sanhedrin in lieu of the nassi (president), the prerogative of the Sanhedrin is effectively neutralized.
The co–opted Sanhedrin of that era indeed later dissolves completely in 68 CE in the wake of the Roman military counter–onslaught, as the Jewish community in Judea implodes under Roman assault, destruction, and subsequent exile in the decade following–upon 68 CE.