desirous to be rated city by city in their due proportion, they gave Aristeides command to survey the countries and to assess everyone according to their ability and what they were worth; and he laid the tax not only without corruption and injustice but to the satisfaction and convenience of all. Aristeides, moreover, made all the people of Greece swear to keep the league, and himself took the oath in the name of the Athenians, flinging wedges of red-hot iron into the sea, after curses against such as should break their vow.[9] The contributions were collected every spring by ten specially appointed men, called Hellenic Stewards, who brought the money to Delos where it was placed in the treasury of the League. The League began its work at once, and one by one the Greek cities in Asia Minor and the islands in the Aegean were set free, until at length not one was left under the rule of Persia. As each city became independent, {182} it joined the League, which grew in strength and importance as its numbers increased. Athens was its acknowledged leader; not only did she determine the amount each member should contribute, but the Hellenic Stewards were all Athenians, and affairs of the League were governed by Athenian law. Slowly the relationship of Athens to the other members of the League changed. At first the states had regarded themselves as allies of each other and of Athens, but as the power of Athens grew, she began to look upon these Greek states less as allies than as subjects who were bound to follow her lead and do her bidding. At length this relationship was so well-recognized that in some states Athens exacted this oath of allegiance from those who enjoyed her protection as members of the Delian League: I will not revolt from the people of the Athenians in any way or shape, in word or deed, or be an accomplice in revolt. If any one revolts I will inform the Athenians. I will pay the Athenians the tribute, and I will be a faithful and true ally to the utmost of my power. I will help and assist the Athenian people if anyone injures them; and I will obey their commands.[10] In name, Athens together with all the island states in the Aegean and the Ionian cities in Asia Minor, were allies and independent. Their envoys still met at Delos, supposedly to take counsel with each other, but in fact they were subject to Athens and obeyed her commands. The League had been formed in 477 B.C. and for twenty-three years Delos was its {183} headquarters. Then it was suggested that the treasury should be moved to Athens, and that the meetings should in future be held there. No longer was Athens merely the leading state amongst her allies. The removal of the treasury from Delos to Athens made her in name as well as in fact not simply the leading state of a Confederation, but the Athenian Empire. III. THE ATHENIAN EMPIRE UNDER PERICLES