Greece saw many different types of governments in the ancient times. Political control in different city-states was different ranging from tyranny to Ancient Greek Oligarchy to democracy.
Ancient Greek Oligarchy
Oligarchy in ancient Greece was common. Ancient Greece Oligarchy basically meant a selected group of people would have the political power. These people were generally rich and influential.
Tyranny in Ancient Greece
In the Greece city-state of Athens, it was believed that any government which did not give political decision-making power to all the citizens and which was not a tyranny or monarchy was an oligarchy. In ancient Greece, oligarchy could be seen in many city-states. An oligarchic government was mostly the result of a democratic government going wrong.
Athens Oligarchy to Democracy
Though there is very little information about oligarchic governments of ancient Greece, there are some references to oligarchy in the city-state of Athens as well as some other parts of ancient Greece. In 411 BC, Athens was ruled by the oligarchy of the 400. Later this oligarchy was ruled out of power by the oligarchy of 5000.
When Athens lost a battle to Sicily, around thirty tyrants formed an oligarchy in Athens. This incident happened in 404 BC and is said to be a brutal period in Greek history. Not just Athens but other city-states like Megara and Thebes also observed an oligarchic government from time to time.
People who formed the oligarchic government and were a part of it were generally rich, mostly big landlords. They also had to be citizens of the city-state to be a part of the political decisions. Also, all over Greece, nowhere were women a part of any kind of government. Hence, Ancient Greek Oligarchy was also a completely male-dominated government system.
Monarchy in Ancient Greece
Hence oligarchies were basically a trade-off between monarchy and democracy, but they might have solved some problems of democracy and monarchy but they never resulted in getting the best of both world i.e. democracy and monarchy and hence oligarchy had its own problems and was never a very successful form of government.