The island tried to secede from the Delian League. After two years Athens finally put an end to the revolt and punished the inhabitants.
Citation:
Bouchard, Elsa. "Revolt of Thasos".
The Literary Encyclopedia. First published 01 March 2010
[http://www.litencyc.com/php/stopics.php?rec=true&UID=11204, accessed 20 May 2013.]