The Jewish Sanhedrim probably took its form from the seventy elders appointed to assist Moses in the government. After the captivity it seems to have been a permanent consistory court. The president was called “Ha Nasi” (the prince), and the vice-president “Abba” (father). The seventy sat in a semicircle, thirty-five on each side of the president; the “father” being on his right hand, and the “hacan,” or sub-deputy, on his left. All questions of the “Law” were dogmatically settled by the Sanhedrim, and those who refused obedience were excommunicated. (Greek, sunedrion, a sitting together.)
The Sanhedrim long time as chief he ruled, Their reason guided, and their passion cooled.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894