Marathon War: Fifth century BC in Athens, the democracy was challenged in two wars, yhich led to its greatness. Athens had the first war to fight against the powerful Persian empire and its emperor Darius. Darius had already occupied territories from the Indus river to Asia Minor, and now he crossed the Aaegean Sea and attacked Greece. His large army came to a place called Marathon near Athens with the help of a fleet. For the first time in the history of Greece, all the states together fought against an enemy. The Greek armies were very fewer in number than is 490 BC. In the battle of Marathon, they fought so bravely that the Persian forces were pushed back.
Peloponician War: Between Athens and Sparta, in 431 BC to 404 BC, there was a Peloponician war. Due to this war, Athens collapsed. At the time of the Persian Wars, Athens formed a union with other Greek kingdoms. After that war, with the help of this union, the power of its navy was greatly increased for its self-suficiency. With this Sparta residents became frightened and animosity grew between Sparta and Athens. In this war some states gave to support Athens and some to Sparta. Athens was defeated in this war. With this democracy was ended from this state.