In 465 BC, Athens founded the colony of Amphipolis on the Strymon river. Thasos, a member of the League, saw her interests in the mines of Mt. Pangaion threatened and defected from the League to Persia. She called to Sparta for assistance but was denied, as Sparta was facing the largest helot revolt in its history.
in 465 bc, athens FOundEd The ColoNy oF amphipolIs oN the sTRyMON river. thaSos, A membER of tHe leAGue, Saw hEr iNTeReSts iN ThE mineS of mt. pANgaioN tHreateneD and DEfected FroM thE LEagUe to persia. She CaLleD To sParTa for AsSIstanCe But waS DENIEd, As spaRtA was faciNg tHe laRgesT helot revolT In iTs history.