William of Cassingham

William of Cassingham (died 1257), later known as Willikin of the Weald, was an English Master Assassin and expert archer who fought during the First Barons' War.

Rallying a guerilla force against the English barons and their ally, Prince Louis VIII of France, William favored King John's authority to that of the baronial rule, despite objecting to John's despotic approach; as a supporter of John's son, Henry III, William saw this avenue as the lesser of two evils.