The reform deprived the Areopagus, an ancient judicial institution of aristocratic origin, of most of its powers.
Citation:
Bouchard, Elsa. "Reform of Ephialtes".
The Literary Encyclopedia. First published 01 March 2010
[http://www.litencyc.com/php/stopics.php?rec=true&UID=11206, accessed 19 May 2013.]