The Panathenaea is an important annual civic festival in honour of Athens' patron goddess Athena. From c. 566 BC the festival was extended every four years to include athletic competitions and was then referred to as the Greater Panathenaea.
Bouchard, Elsa. "The Greater Panathenaea". The Literary Encyclopedia. First published 01 March 2010
[http://www.litencyc.com/php/stopics.php?rec=true&UID=11161, accessed 29 August 2014.]