The Delian League was an organisation established in the early 5th Century BC by several Greek states to defend themselves from the Persians, whom they had already defeated in the Graeco-Persian Wars. To modern readers it may seem unnecessary to defend yourself from a people you have already defeated, but the Persian Empire was still powerful, and besides, part of the reason for the League was to get a little payback for the devastation the Persian forces had caused in some areas of Greece.
Formation of the Delian League
Accordingly, Greek forces consisting of Athenians (including Xanthippos1, the father of the Greek statesman Pericles) and Greeks from Ionia2 and the Hellespont3 besieged Sestos, a city held by the Persians. After a year they took the city.
Following this, the Greek fleet, led by Pausanias, a military commander from the city-state of Sparta, sailed to Cyprus where they freed Greek cities which had been under Persian control, as well as capturing the city of Byzantium. After some time, Pausanias was recalled as the other Greeks were not happy with his behaviour, which may have included taking up Persian customs. Obviously, the Greek forces would not have been happy seeing their leader acting like the enemy. Between Pausanias's recall and the arrival of his Spartan replacement, the leaders of Lesbos, Chios and Samos, the three largest islands between Greece and Ionia, entered discussions with Athens to have the Athenians lead them instead of the Spartans. When agreement was reached, the Delian League was formed in 477BC.
The Organisation and Administration of the League
According to Thucydides, a famous Greek historian who lived only a few decades later, the arrangement of the Delian League was in the form of an alliance designed to gain some form of compensation for the troubles and losses undergone by the Greeks during the war by plundering the lands of the Persians. Its main purpose, though, was to protect the Greeks who had recently been freed from Persian control, and to liberate more Greek cities. Representatives of the member states threw a block of metal into the sea and swore friendship until it rose again. Of course, since metal can't float, it meant friendship in perpetuity. In reality, it lasted less than a century, proving the folly of making such vows.
The Delian League is so-named because it was based on the Greek island of Delos. This island was the perfect base for a number of reasons. It was too small to have any political ambitions of its own, it was not located too close to Persian territory, and legend has it that Delos was the birthplace of the god Apollo and goddess Artemis.
The alliance was voluntary, and a condition of membership was that each state had to contribute a number of ships, or if they preferred, to provide an equivalent amount of money. The amount of ships or money they had to provide differed depending on their size. Aristeides, the Athenian general who had negotiated with the island leaders about the take-over from the Spartans, was allowed to decide the contributions as he was famous for his honesty. Apparently all the member states trusted him enough to allow this. The money was initially stored in a temple on Delos as it was thought that the Gods would protect it, and because temple robbing was seen as a particularly heinous crime.
The exact number of members of the League is unclear, though it was less than 200. All member states were entitled to contribute ideas at meetings of the League, and all member states had only one vote regardless of size or power. However, the Athenians took unofficial leadership from the start. It was their officials, known as Hellenotamiai, which translates as 'treasurers of the Greeks', who administered the funds of the League. Athens also provided the military leaders. While all votes were equal, the influence exerted by each state on their fellows was not.
The Peace of Callias
The Peace of Callias was a peace treaty which may have been made between the Delian League and the Persian Empire in around 450BC. Part of the agreement was that all the Greek cities in Asia Minor should be free.
However, some historians debate whether the Peace even occurred. The reason for this uncertainty is that the Peace is referred to in the work of Diodorus, but not in the history of Thucydides which is widely regarded as very reliable and accurate. Some later sources deny its existence altogether. Most historians now accept that there was a peace, because there are no records of fighting between the Delian League and Persia after this time.
Problems in the Delian League and Development into the Athenian Empire
The power and influence of the Athenians within the League greatly increased over time and it grew to become more of an Athenian Empire than an organisation in which every member was at least nominally equal. Athens was like the bullying leader of an increasingly unwilling gang. States even began to be forced to join the League.
Over time many members wished to withdraw from the League, probably because of the growing power of the Athenians and the fact that Persia no longer seemed to pose a threat. Athens did not react well to this, responding with their considerable military might to defeat the rebels and force them to remain in the League. If the rebel state had given up ship building for the League, the Athenians, who had the strongest navy of any Greek state, would have a big advantage. Once defeated, the usual treatment was for whatever fleet they may have had to be confiscated and to have their city walls pulled down, if they had them.
The growing power of the Athenians is easy to see in the way they took action to change the other member states and introduce uniformity wherever possible. One way they did this was by issuing a decree which forced the members of the League to adopt Athenian coins, weights and measures. This was a big advantage to Athens as a centre of trade, but was something of a loss of sovereignty for the member states. Members were still referred to as 'allies' in official documents, but they were clearly subjects - as demonstrated by the fact that they had no say in this decree.
The power of Athens is also shown in their treatment of defeated rebel states. Not only did they demand sizeable monetary reparations, and if applicable, would seize the fleet of their enemies and pull down their city walls, but they would force defeated rebels to swear oaths of loyalty to Athens. They were cocky enough to consider that they had the right, and they certainly had the power, to remove the civic rights of the other cities of the Empire, which they sometimes used as a punishment. Being a citizen was very important to the ancient Greeks, so this was a terrible penalty.
The gradual change to an Athenian Empire can also be seen in the way the Athenians transferred the League's treasury to Athens in around 454BC. Eventually the situation forced even Samos, one of the founder-states of the League, to revolt. This was a serious threat to Athens as Samos was one of the only states who could come close to matching their navy – they were one of the few members who still provided ships rather than money. After a year, though, they were forced to surrender.
The Athenians eventually had enough control over their Empire to vote to use the money provided by the members of the so-called League, for what historians call 'The Periclean building programme', a series of new buildings in Athens, which included the Parthenon. This may well have been seen by the other members as a slap in the face.
The change from the nominally equal Delian League to the Athenian Empire did not happen overnight. However, from about 450BC onwards, the Athenians began to refer to the cities of the League as 'the cities that the Athenians rule'. The Athenians also sent officials to advise the other cities of the Empire – which translates as trying to influence them. Decrees about the Empire did not refer to any of the supposedly allied cities being consulted, never mind agreeing to it.
Advantages of the Empire
Despite the unpopularity with which Athens and its Empire may have been viewed in some quarters, it did have some advantages to the allied cities. For one, a single system of coinage, weights and measures made trade easier. Secondly, Athens did provide a strong military force in the region, whether for protection from Persia or pirates. Smaller states would have been unable to chart their own political course anyway – such states are always dominated by their larger neighbours. Finally, the Athenians were very keen on democracy (no surprise, since they invented it) which was advantageous to the poor of the Empire as it gave them more power over their own lives and the actions undertaken by the state.
End of Empire
The end of the Athenian Empire occurred later in the 5th Century. Athens and her allies were losing to perennial rival Sparta and her allies in the Peloponnesian War. The Spartans had engaged their old enemies the Persians to help, which they did by providing money. In addition, the Athenians had suffered terrible losses to their fighting men and navy during the so-called 'Sicilian Expedition', when they were defeated by some of the Sicilian cities, led by the city of Syracuse and helped by the Spartans.
Some of the cities of the Empire took advantage of the distraction of Athens and unavailability of her military to revolt, encouraged by the Spartans. Eventually, Athens was forced to surrender. One of the conditions of surrender was to give up the Empire, and Athens had no choice but to comply. There was a Second Athenian Empire some years later, but it was just as short-lived.