In 507 B.C., Athenian ruler Cleisthenes introduced a series of governmental reforms known as "demokratia" -- democracy, or rule of the people. Male citizens over the age of 18 were eligible to directly participate in the city-state's government. All who participated were paid for their service. While the structure may seem very different from modern republican democracies, the idea of government by the people became one of ancient Greece's most enduring legacies.

The People's Assembly

The ekklesia, or people's assembly, was the central institution of ancient Athenian democracy. Citizens of Athens gathered 40 times a year to write or revise laws, issue decrees and make foreign policy decisions by simple majority vote. All citizens present could speak, regardless of their age or standing in society. The assembly wasn't quite as egalitarian as it may seem, however. Only adult male citizens could participate -- in practice, this amounted to between 10 and 20 percent of the Athenian population. Although an estimated 40,000 individuals were eligible to participate, only between 5,000 and 7,000 citizens actually attended any given meeting.

The Council of 500

As its name suggests, the Council of 500 was made up of 500 men, 50 from each of the ten tribes of Athens. These men were chosen by lot from Athenian citizens to serve one-year terms. Each citizen could serve as many as two non-consecutive council terms in his lifetime, and 75 percent of Athenian men over the age of 40 had served at least once. The Council's job was to vote on preliminary laws and decrees that would be passed on to the Assembly for final ruling. The Council met daily, voting on proposals and setting the agenda for the next meeting of the Assembly.

Rotating Presidents

Direct democracy can be a slow process, so in crisis situations Athens depended on its presidents to make short-term, emergency decisions. Ancient Greece divided the legislative year into 10 parts. Each tribe's 50 councilors served jointly as presidents for a single part, or "prytany." At the end of one prytany, the tribe that would preside over the next prytany was chosen by lot. This process sought to limit corruption by assuring no one knew which tribe would serve next. Aside from handling emergencies, the presidents planned and organized each day's council meetings.

The People's Court

The people's court in Athens arguably had the most power of any of the Greek democratic institutions. Each day, more than 500 jurors would be chosen by lot from the pool of male citizens over 30 years of age. These jurors had almost unlimited power in the civil and criminal cases they heard. Ordinary citizens brought and argued cases -- Athens didn't have police or attorneys. Once both sides had been heard, jurors cast their ballots, deciding verdicts based on simple majority rule. The court also heard cases brought from citizens dissatisfied with a law or decree issued by the Assembly -- an ancient version of today's judicial review. There was no way to appeal any part of the jury's verdict; all judgments were final.