Classical period of Greek history dates about 500 B. C., when the Greeks started to come into conflict with the kingdom of Persia to the east, and the death of the Macedonian king and conqueror Alexander the Great in 323 B.C. In 510 BC a man known as Cleisthenes, who was an aristocrat in Athens, invented another new type of government, the democracy. Cleisthenes, like other aristocrats, wanted to get more supremacy, for this reason he decided to give even more authority to poor people. He organized a new way of making political decisions. Every Athenian man would have one vote, and they would all meet and vote on what to do. The big meeting was called the Assembly. But all the men couldn't meet every day; they had to work. So there was also a smaller council of 500 men, who were chosen by a lottery, and changed every year. Cleisthenes and the other aristocrats would be out of supremacy, but he arranged the voting so that his family, the Alcmaeonids , would have more votes than anyone else.
In 490 BC the Persians confronted Athens. Everybody was very afraid, because the Persians were great warriors. Some people thought Athens should go back to the old system of government, the oligarchy, in case democracy didn't work well enough. They thought it would take too long to make decisions in a democracy. But they didn't go back. All the men in Athens marched out to meet the Persians at Marathon. They thought they would lose. But the Athenians fought in the new way, with the wall of shields, and the Persians were still running and yelling. So that the Athenians won.
In 480 BC the Persians, with their king Xerxes confronted again. This time most of the towns in Greece associated together and formed a league to fight the Persians. They lost their first battle, at Thermopylae , but they won after that, at Salamis and again at Plataea . Again the Persians went conquered.
The Athenians induced to the other Greek towns in that they needed to keep the strong Greek navy together in case the Persians came back again. At first everyone thought this was a good idea, except the Spartans, who refused. Then the Athenians said to the other towns, "Don't bother sending ships and men for the navy anymore; that is too hard. Just send money to Athens, and we will build ships and protect you against the Persians." So a lot of towns did that. But the Persians did not come back. After a while, some of the towns said, "We don't want to send any more money to Athens. We don't think the Persians are going to come back anymore." But the Athenians used their big navy to make the other towns keep sending money. When Miletus denied, the Athenians took their town and destroyed it. The Athenians also spent some of the money on their own town. No Athenians had to pay taxes anymore. They used the money from the other towns to erect great temples like the Parthenon. The other towns in Greece were angry. They asked the Spartans to help stop the Athenians. Some towns took sides with Athens, others with Sparta. There was a big war, from 431 BC to 404 BC (almost thirty years). This is called the Peloponnesian War. But finally, with the help of the Persians, the Spartans won and the Athenians lost. By this time, all of Greece had pretty much been worn-out, and the Classical period was over.