The disappearance of Simon, also known as Simeon, was the cause of a major blood libel in Europe with ramifications that lasted almost five centuries. Shortly before Simon went missing, Bernardo da Feltre, an itinerant Franciscan preacher, had delivered a series of sermons in Trent in which he vilified the local Jewish community. When Simon went missing around Easter, 1475, his father concluded that he must have been kidnapped and murdered by Jews. According to his story, the Jews had drained Simon of his blood for use in baking their Passover matzohs.
The leaders of the Jewish community were arrested, and seventeen of them confessed under torture. Fifteen of them, including Samuel, the head of the community, were sentenced to death and burned at the stake. Meanwhile Simon became the focus of adoration for the local Catholic Church. Over one hundred miracles were directly attributed to "Little Saint Simon" within a year of his disappearance, and his cult spread across Italy and Germany. He was beatified in 1588 by Pope Sixtus V and considered a martyr and a patron of kidnap and torture victims.
In 1965, in the wake of the Second Vatican Council, the Church began to reinvestigate the story of Saint Simon and opened the trial records anew. Finally declaring the episode a fraud, the cult of Saint Simon was disbanded by Pope Paul VI and the shrine erected to him was dismantled. He was removed from the calendar, and his future veneration was forbidden.
Although historians agree that it is highly unlikely that Simon was murdered by Jews, the murder is still promoted as a fact by a handful of extremists. The actual cause of Simon's dissappearance remains a mystery. (http://188.8.131.52/search?q=cache:SsSDYbsYq64C:www.ostara.org/e-books/trent.htm+Saint+Simon+Trent&hl=en&ie=UTF-8)