<P> In the first ten years of the league's existence, Cimon / Kimon forced Karystos in Euboea to join the league, conquered the island of Skyros and sent Athenian colonists there . </P> <P> Over time, especially with the suppression of rebellions, Athens exercised hegemony over the rest of the league . Thucydides describes how Athens's control over the League grew: </P> <P> Of all the causes of defection, that connected with arrears of tribute and vessels, and with failure of service, was the chief; for the Athenians were very severe and exacting, and made themselves offensive by applying the screw of necessity to men who were not used to and in fact not disposed for any continuous labor . In some other respects the Athenians were not the old popular rulers they had been at first; and if they had more than their fair share of service, it was correspondingly easy for them to reduce any that tried to leave the confederacy . The Athenians also arranged for the other members of the league to pay its share of the expense in money instead of in ships and men, and for this the subject city - states had themselves to blame, their wish to get out of giving service making most leave their homes . Thus while Athens was increasing her navy with the funds they contributed, a revolt always found itself without enough resources or experienced leaders for war . </P> <P> The first member of the league to attempt to secede was the island of Naxos in c. 471 BC . After being defeated, Naxos is believed (based on similar, later revolts) to have been forced to tear down its walls, and its lost its fleet and its vote in the League . </P>

What large island was part of the athenian empire