Bernardon Giovanni was the son of a wealthy businessman and his French wife, the parents' house can be visited today. As a young man he got the nickname Francesco because of his inherited from the mother's preference for the French language and chivalrously-courtly life. He led a happy and carefree life and wanted to be knights. After a battle between Assisi and Perugia, he was more than a year in Perugia detained and suffered during his captivity from a serious illness, it led to his conversion. 1203, he was freed from captivity, returned back to Assisi, undertook a pilgrimage to Rome and maintained lepers. Even in those days was regarded as eccentric and he had to suffer ridicule, but he was like a deaf patient with a cheerful face and through the crowd. His father made himself thought, what the son might have such composure despite all the insults and contempt of such world-motivated.

For the restoration of the small church of San Damiano Francis sold in 1207 some Tuchballen from the possession of his father and was involved in the speech made; Francis discarded the tradition as an answer before the eyes of the bishop and a large amount of viewers of all his clothes entsagte and the legacy with the words "neither money nor clothes I want from you, from now on I call only one father, in heaven!" He ran naked from the city and adopted as the origin and society. 1207 to 1209 he led a hermit life, meanwhile, he will oversee the construction of two other churches destroyed ascribed.