Depending on the widely varied constitutions, it applied to diverse representative or judiciary organs of Greek and Hellenistic city-states and treaty organisations.
Inside the Council ruled the democratic principles of isegoria (equality of word) and of parrhesia (freedom of speech), to which the king subjects himself like the other members.
After the removal of the Antigonid dynasty by the Romans in 167 BC, it is possible that the synedrion remained, unlike the Assembly, representing the sole federal authority in Macedonia after the kingdom's division into four merides .
Josephus uses συνέδριον for the first time in connection with the decree of the Roman governor of Syria, Aulus Gabinius (57 BC), who abolished the constitution and the then existing form of government of Israel and divided the country into five provinces, at the head of each of which a synedrion was placed.
[2] In 57–55 BC, Aulus Gabinius, proconsul of Syria, split the former Hasmonean Kingdom into Galilee, Samaria & Judea with 5 districts of synedrion (councils of law).