The crisis was soon reached. War broke out between the King and his
brother-in-law, Simon de Montfort, Earl of Leicester (S209), better
known by his popular name of Sir Simon the Righteous.
With fifteen thousand Londoners and a number of the barons, he met
Henry, who had a stronger force, on the heights above the town of
Lewes, in Sussex. (See map facing p. 436.) The result of the great
battle fought there was as decisive as that fought two centuries
before by William the Conqueror (S74), not many miles distant on the
same coast.