Henry V was attempting to enforce his claim to the throne of France. He invaded France in August, 1415. His original force of eleven thousand men was reduced by disease and warfare. However, a large French force precipitated a battle at Agincourt. Against all odds this proved to be a remarkable English victory.
Editors. "Henry V invades France and gains victory at Agincourt". The Literary Encyclopedia. First published 01 March 2010
[http://www.litencyc.com/php/stopics.php?rec=true&UID=9639, accessed 11 February 2016.]