In The Greeks Had a Word for It: Hegemony vs. Empire, Lee Harris explains where the word “hegemony” comes from:
The word is Greek: it means the leadership of a coalition or an alliance, and it was used in this sense by the Greek historian Herodotus and Thucydides. But since English has a number of perfectly good words to indicate leadership, such as chief, head, principal, boss, manager, organizer, general director, and so forth, few users of the English language felt any need to rescue this word from its moldy niche in the Greek lexicon until the mid 1840′s when the English radical and banker George Grote began publishing his monumental History of Greece, a work of immense scholarship that is still wonderfully fascinating.Curiously enough, in light of its current usage, the reason Grote decided to revive the Greek word hegemony was in order to distinguish it sharply from the Latin-derived word with which it has now become inextricably muddled, namely, the word empire.
Athenian hegemony eventally devolved into empire, but only after a successful run:
Athenian hegemony had first emerged in the aftermath of the Persian wars — wars in which the colossus of the Persian empire had tried to transform the various independent Greek city-states into tribute-paying colonies, using a combination of bribery, diplomacy, and overwhelming military force. In the course of the struggle against Oriental imperialism, Athens, with its great naval power, had ended up as the Greek city-state that was in the best position to defend against further Persian invasions — an indisputable fact that became the basis of a post-war defensive coalition developed by Athens and its allies in order to afford protection for the various Greek city-states spread across the Aegean Sea, on islands such as Samos, Chios, and Lesbos, as well as along the Ionian mainland — all of which had been targets of the previous Persian invasions, and could easily become targets once again.This defensive confederation was called the Delian League, after the island of Delos where it was first headquartered. Originally devised to keep the Persian Empire at bay, its initial role was not terribly different from the role that NATO played vis-?-vis the Soviet Union during the Cold War. Furthermore, like NATO, the Delian League worked: during its existence, the Greek city-states that were its members were free both from Persian invasion and tribute obligations. Indeed, thanks to Athenian naval supremacy during this period, the Aegean Sea was even freed from the eternal maritime pestilence known as piracy.
In the beginning, the members of the Delian League were required to produce ships and sailors capable of rallying to the defense of the Greeks against Persian assault, but over time the various city-states under the protective umbrella of Athens began simply to pay Athens for the services rendered by its huge and extraordinarily competent navy. Athens did not make this happen — it was the will of the various commerce-minded city-states whose prosperity was more important to them than their ability to defend themselves with their own fleet and crew.
Unfortunately, the payment of money from the confederates gradually came to be seen as a kind of imperial tribute — analogous to the tribute money that the Persian Empire itself exacted from the various regions over which it governed, and soon what had started out as a coalition under the leadership of Athens became a maritime empire that was operated by the Athenians solely for the profit of the Athenians. Indeed, the day would come when the rule of Athens would become as brutal, if not more so, than the rule of the Persian empire, and city-states that had once been the allies of Athens would revolt from its rule, seeking to regain the autonomy that they had lost. Though the Persian forces of Darius and Xerxes had been repelled, the poison of Oriental despotism had begun to corrupt the egalitarian ethos of the Greeks. The Persian King owed his vast wealth to the huge amount of tribute that he could force his satrapies, or colonies, to pay him. Why couldn’t Athens play the same game?