In a biography of Leonardo da Vinci, it is argued that he felt compelled to stay in Milan longer than he had intended after meeting with the young Francesco.[5] Francesco is described in literature as charming and graceful, an adolescent without the awkwardness or lack of manners typical of boys around this age.[5] Francesco and another pupil of Leonardo's, Boltraffo, stood out from the other students as they were capable painters, very bright, and well-learned.