St. Francis of Assisi (c. 1181-1226) and Jacopone da Todi (c.1236-1306) were but two exemplars of a rich school of mystical poets writing in Umbria in the Franciscan religious tradition. Their powerful creations form a significant corpus of medieval Italian vernacular poetry only now being fully explored.

Drawing on a wide range of literary, historical, linguistic, and anthropological approaches, Vettori crafts an innovative portrait of the artists as legends and as poets. He investigates the essential features of emerging Franciscan tradition, in motifs of the body, metaphors of matrimony, and musical harmony. Vettori also explores the relationship of Francis's poetic mission to Genesis, the relationship between erotic love and ecstatic union in both poets' work, and the poetics of the sermon.