Mytilene was one of the last non-tributary members of the Delian League which chose to man their own warships and send subjects to fight alongside the Athenian fleet. Mytilene feared tributary democracy and did not want to be reduced to the status of other Athenian allies. In addition, Mytilene was different from most allies because it was ruled by an oligarchy. Mytilene had contemplated ending its alliance with Athens, but Sparta had rejected its appeal for an alliance to enable this. However, this rejection had been prior to the outbreak of the Peloponnesian War, which created an opportunity for the Mytilenians, who sent an envoy to Olympia in 428 B.C. to seek assistance from the Peloponnesians. The Mytilenians asked for direct help in Mytilene, but also for an invasion of Attica, pointing out that since Athens had recently been devastated by a plague it would have financial difficulties fighting on two fronts.