because their smart
After defeat, Athens was stripped of its empire, and without the revenues they mulcted from it, they were not able to either maintain naval preeminence or afford the expenditures which had supported such extravagances as the beautification of Athens.
spartans have the control in athens
The Delian League was defensive, and protected the Greek city-states, not to take over Anatolia, which remained under Persian control except for the Greek cities. The 180 cities of the Delian League paid for the navies of Athens, Samos, Chios and Lesbos which were able to keep the Persian navy away and provide ground support for threatened cities. After 30 years the Persians gave up trying to regain control of the cities and left them to their own devices, agreeing in the Peace of Callias not to go beyond specific lines by sea, and accept the independence of the Greek city-states in Asia Minor. Athens the Persian threat subsided, Athens converted the Delian League into an empire of its own and used its war contributions for its own benefit, and used the League resources to try to dominate Greece, leading to the Peloponnesian War against the Peloponnesian League led by Sparta. After losing this war by 404 BCE, Athens was stripped of its empire, and became a second rate power. A short time later Persia took the opportunity to reabsorb these cities in Asia Minor and impose the 'King's Peace' on the still-warring Greek city-states in mainland Greece, whose fighting was spilling over into the Persian Empire.
After peace was agreed, Athens was able to convert the Delian League which it had led, into an Empire of its own, and brought on the 27-year Peloponnesian War which devastated the Greek world.
You can't exactly pin-point an exact date for this transformation as the Delian League gradually progressed toward becoming the Athenian Empire. How it did this was through Athens slowly increasing their level of control over their allies. They increased their control in a number of different ways. For one, as soon as a member of the League became rebellious Athens would take their autonomy and use their navy to suppress them. Also, the allies had to pay tribute or provide ships, many would decide that the upkeep for these ships and the risk of losing men on lengthy expeditions was too much so they would resort to paying the tribute instead. This was beneficial for Athens as they would be the only ones with a great navy because the allies (which were islands) would be lacking in experience and Athens could happily then spend the tribute money on reinforcing their own navy. Additionally, Athens being the bigger and better member of the League and quite clearly the leader as such, would have the most influence in the council of the League. Being that they were able to intimidate the members into voting a certain way. There are many events that lead to the D.L becoming the A.E and I could probably talk about it forever... hope this helps?
Because the tyrants forced a traded democracy.
They were built in the second half of the 5th Century BCE when Athens had turned the anti-Persian Delian League of 180 city-states it had led, into an empire and was able to mulct their resources to get the money to create a massive building effort.
There were two major groupings of city-states - the Athenian league/empire, and the Peloponnesian League led by Sparta.Initially Athens which had led the Greeks in the second half of the wars, and when peace was arranged, turned the Greek coalition, which it led, into an empire of its own. It used this to try to dominate the Greek world, but over-reached itself and was defeated and stripped of it empire, leaving Sparta as dominant power until Thebes displaced it. All this so weakened the Greek cities that Macedonia was able to dominate them.
In the later stages of the war it led the Delian League to protect the cities against the Persians, taking financial contributions from the cities to maintain the fleet which protected them. When Persia finally agreed to stay away from the cities, Athens continued to collect the contributions from the cities and maintain a superior navy, and used the surplus to glorify the city and keep half its population on the public payroll, and using the war fleet to collect the funds by force if necessary, and effectively turning the League into an empire. This, plus the walls it built around the city and its harbour, made Athens overconfident and interfering in other states, resulting in the Peloponnesian War in which the Greek world was devestated over 27 years, and a defeated Athens lost its empire and became a second rate power.
After seeing off the Persian threat, the Greek cities were able to return to their habitual shifting alliancces and disputes. The diffrence this time was that Athens, had organised the anti-Persian defensive Delian League to ensure the cities of Asia Minor and the Islands were free from the Persian threat. When peace was finally formalised after 449 BCE Athens shifted this Delian League treasury from the island of Delos to Athens and then began to spend it on itself, building the Parthenon etc and putting nearly half its population on the payroll, and paying for its fleet to continue collecting League contributions by force if necessary. This League therefore became effectively an empire of Athens, and Athens was thus enabled to use its power to intervene in other cities' affairs outside its empire. Sparta was prevailed on to lead a Peloponnesian League as a counter (most were Dorian cities in peninsular Greece - the Peloponnese). So the threat of Persia was replaced with threat of war between two powerful internal Greek coalitions, which came devastatingly into play with outbreak of the Peloponnesian War in 431 BCE. Paradoxically, this war was decided against Athens after 27 years by the late intervention of Persia on the side of the Peloponnesians.
This is not an easy question to answer simply. First you must understand that ancient Greece was never a united empire like Egypt or rome. Each Greek city was independent of all others. the exceptions to this were the delian league which was really more of an Athenian empire because Athens had the largest navy at the time, after the Persian wars.Delian....Empire?After Xerxes I's invasion of Greece in 480BC, a collection of city states grouped together as a way of getting their own back and protecting themselves from the Persian threat. Athens, at the Head of the Delian League was in a position of Authority over the others. She contributed the most ships, and organised the treasury. All nice and happy. But not for long. Once the Persian threat had long since gone, a few states decided they no longer wanted to pay the tribute to keep the league running and tried to leave. Athens was having none of this. Athens quickly began to intimidate the other states with her vast navy. This happened until the League treasury, on the island of Delos, was moved. To Athens. From this point on, the pact of city states began to look very much like an Athenian empire. Sparta, at the head of it's own league, the Hellenic League, was having none of this. The Pelopponesian War broke out, Athens began by winning, but after the death of Pericles in an outbreak of measles, Athens hadn't a hope. Sparta ended their empire.
A peace was made with the Persian Empire. Athens converted the Delian League into an empire of its own and used the proceeds to enrich itself. It also used this power to intervene in the Greek cities outside this League, and this brought it into collision with the Peloponnesian League led by Sparta, resulting in the devastating 27-year Peloponnesian War. Athens lost, as stripped of its empire, and became a second rate power.