Guy de Montfort, Count of Nola (1244 – 1291) was the son of Simon de Montfort, 6th Earl of Leicester and Eleanor of England.
He participated in the Battle of Evesham against the royalist forces of his uncle, King Henry III of England, and his cousin, Prince Edward. Both his father and elder brother were traumatically killed during the disastrous battle, Guy de Montfort was extremely wounded and captured.
He was held at Windsor Castle until spring 1266, when he bribed his captors and escaped to France to rejoin his exiled family. Guy and his brother, Simon the younger, wandered across Europe for several years, eventually making their way to Italy.
Guy took service with Charles of Anjou, serving as his Vicar-General in Tuscany. He distinguished himself at the Battle of Tagliacozzo and was given Nola by Charles of Anjou.
In 1271, Guy and Simon discovered that their cousin Henry of Almain (son of Richard, Earl of Cornwall) was in Viterbo at the church of San Silvestro. In revenge for the deaths of their father and brother at Evesham, on 13 March, 1271, Guy and Simon murdered Henry while he clutched the altar, begging for mercy. "You had no mercy for my father and brothers", was Guy's reply. This murder was carried out in the presence of the Cardinals (who were conducting a papal Election), of King Philip III of France, and of King Charles of Sicily. For this crime the Montfort brothers were excommunicated, and Dante banished Guy to the river of boiling blood in the seventh circle of his Inferno (Canto XII).