Just saw this event and thought it might be nice to visit if you are in the country at the time:

England's Medieval Festival - 27, 28 & 29 August 2005
Herstmonceux Castle, East Sussex, England
http://www.medieval.co.uk/

"In this magical setting history will come to life. Over 1000 knights, bowmen and men-at-arms will lay siege to the castle. England's largest medieval battle with full cannon support. Daily at 11am & 3pm. [how convenient!]"

Gareth