How did the democratic government in Greece develop?

Around 510 BC, a wealthy Athenian named Cleisthenes planned to distribute political power to the populace. He came to power after the overthrow of Hippias, who was a tyrant, and of Isagoras (his onetime ally) who tried to usurp the Athenian councils and rule Athens.

His new government included all Athenian men, using a gathering called the Assembly. But because getting everyone together was difficult, a smaller group of 500 men, the Boule, would be chosen each year by lottery, and would handle most of the work of legislating and administering the city-state's public business. Only a few important decisions would require a city-wide vote.

The Boule would have representatives from each of ten clans, called "phyles" (tribes) each created from three regions: one urban, one inland, and one seacoast. Because the Boule members were chosen at random, it was not exactly a representative democracy of the modern form. Clisthenes and his clan were successful for awhile in controlling much of the power in Athens. He called his system isonomia (equality under the law) rather than democracy.

The Progression of Rule in Athens
Monarchy was first. it was rule by one. Then came oligarchy, rule by a few. Tyranny was third on the list. it was rule by authority or force, by power. Finally, the ancient Greeks were known for democracy, where everyone has a say in the system of government.