Gubbio was an important ancient Umbrian town and contains the second-largest surviving Roman theater in the world. Gubbio was very powerful in the beginning of the Middle Ages, sending 1,000 knights to fight in the First Crusade. The city is the setting for the popular story of St. Francis and the Wolf of Gubbio, recorded in the medieval Fioretti di San Francesco (Little Flowers of Saint Francis of Assisi). According to the legend, the wolf terrorized the city of Gubbio until St. Francis of Assisi tamed it. The text was the inspiration for the Roberto Rossellini’s 1950 film Francesco, Giullare di Dio(“Francis, God’s Jester”), which was co-written by Federico Fellini. It was also used as a source for the libretto of Olivier Messiaen’s opera "Saint-François d'Assise." The Church of S. Francesco dates from the second half of the thirteenth century. The frescoes date from the fifteenth century.