The final steps in the shift to empire may have been triggered by Athens' defeat in Egypt, which challenged the city's dominance in the Aegean and led to the revolt of several allies, such as Miletus and Erythrae. Either because of a genuine fear for its safety after the defeat in Egypt and the revolts of the allies, or as a pretext to gain control of the League's finances, Athens transferred the treasury of the alliance from Delos to Athens in 454–453 BC.