Trial of Socrates
In Athens, the jury system was introduced simultaneously with Athenian democracy in 590 BC. A council called Areopagus consisting of elected aristocrats, ran both the government as well as the court.
Pericles and his predecessor Aphialtes, had accomplished one of the greatest reforms in the judicial system that of .transference of the judicial powers from this council of aristocrats, to the heliaea, a law council consisting of 6000 jurors, annually drawn by lots from the citizen's register. Only male citizens over thirty years of age were permitted to volunteer for jury duty. Women and slaves as well as alien residents were not permitted. These 6000 jurors were divided into 10 panels of roughly 500 jurors each. Jury duty was voluntary and each juror served for a year at a time. Pericles also began the practice of a fee of three obols for a day of jury duty. Athens employed panels ranging from 500 to as many as 1500 jurors, depending on the nature of the case. Using a large number of jurors prevented bribery and the panel before which a case was to be tried was decided by lot at the last minute to reduce corruption. All jurors swore an oath by the gods Zeus, Apollo and Demeter:
"I will cast my vote in consonance with the laws and decrees passed by the Assembly and by the council, but, if there is no law, in consonance with my sense of what is most just, without favour or enmity. I will vote only on the matters raised in the charge, and I will listen impartially to the accusers and defenders alike."