Historical version 2 of William Of Ockham (view current version)
William of Ockham (also Occam) (ca. 1285-1349) was a Franciscan friar and philosopher from Ockham, Surrey. Perhaps now most famous for Occam's Razor, he is regarded by many as one of the greatest logicians of all time.
Accused of heresy, Ockham was summoned to Avignon by Pope John XXII in 1324, where he became drawn into the debate between the Franciscans and the Papacy on the doctrine of apostolic poverty, eventually condemning the Pope as a heretic. (At this point, you should go and read Umberto Eco's The Name of The Rose.) He fled Avignon and was given protection by Louis IV of Bavaria, probably being excommunicated in the process. He spent the remainder of his life writing about political issues, eventually dying in a convent in Munich.