Athens was its undisputed leader and gradually used the alliance as a springboard for its own imperial ambitions. By 454, when the League's treasury was transferred to Athens and used to fund monuments of imperial splendor such as the Parthenon, it had become an empire in all but name.
Explanation:
This money was supposed to build the power of the league. ... The result of the Delian League's treasury being moved to Athens from Delos was Athens power was strengthened and they starting to treat the other members of the league as if they were conquered people, not allies.
