This is one of few painting whose attribution to Leonardo has never been questioned. It is a portrait of St Jerome, who  was one of the founders of the Roman church and is said to have translated the bible into Latin. He represents scholarship and asceticism as he lived as a hermit and founded a school and monastery in Bethlehem. Included in the lower right corner of this picture is a lion, which legend has it that he removed a thorn from the paw of, after which it  companionized him. This piece is a characterizing piece of Leonardo's as it shows his knowledge of human anatomy.