Before the Persian Wars the Greeks did not rely on public fi nance to fi ght each other. Th eir hoplites armed and fed themselves. But in the confrontation with Persia this private funding of war proved to be inadequate. Th e liberation of the Greek states beyond the Balkans required the destruction of Persia's seapower. In 478 Athens agreed to lead an alliance to do just this. Already it had Greece's largest fl eet. Yet, each campaign of this ongoing war would need tens of thousands of sailors and to go for months. No single Greek state could pay for such campaigns. Th erefore the alliance agreed to adopt the Persian method for funding war: alliance members would pay annually a fi xed amount of tribute. Th is enabled Athens to force Persia out of the Dardanelles and the Anatolian seaboard. Nevertheless the Athenians also realised that their military might depended on tribute and so tightened their control of its payers. In so doing they turned the alliance into an empire. By 450 Athens had become a threat to Greece's other dominant power. Sparta, however, struggled to meet this threat eff ectively. In the Peloponnesian War the Spartans realised that they could only do so if they too became a seapower. But their state's weak fi nances ruled this out. All changed in 412, when Persia's Great King decided to give it the necessary funds. In exchange for the right to levy tribute again on Anatolia's Greeks, he helped the Spartans to acquire a large fl eet. In 405 this fl eet captured the last warships of Athens. Sparta could now dismantle the Athenian empire and force Athens to surrender by a land and sea blockade. In the Corinthian War the Persians initially funded the anti-Spartan alliance, because the Spartans had decided to fi ght them for control of Anatolia's Greek states. Th e Athenians used Persia's gold to rebuild their fl eet. With these warships they set out to re-establish the Athenian empire. But this represented a still bigger threat to Persia. Consequently the Great King switched his funding to the Spartans. Th ey quickly assembled a fl eet terms of use, available at https://www.cambridge.org/core/terms.