Simon de Montfort, 5th Earl of Leicester
Simon de Montfort (1170-1218), 5th Earl of Leicester was a French nobleman, notable for his ruthlessness as a leader of the Albigensian Crusade against the Cathar heretics in southern France from 1209. Whilst his participation can be seen as part of a cynical drive for power and land in a region long considered apart from mainstream French culture and politics; his well-documented barbarity must be balanced against his decision, whilst a member of the notorious Fourth Crusade not to participate in the sack of Constantinople in 1204; instead making his own way to the Holy Land. This shows a moral standard at odds with his later actions in Languedoc, which can be laid down to the perceived importance of strict orthodoxy as a part of religious devotion.
Through his mother, he claimed the earldom of Leicester from King John after 1204. John initially granted the honour but confiscated the lands and title in 1207. They were returned to his son, Simon de Montfort, 6th Earl of Leicester by Henry III.
Reference: The Oxford Companion to British History 1997 p.652