Leone, a Papal guard, is devastated when his wife drowns herself after mistakenly thinking that he had abandoned her. He turns over his son David to be brought up by nuns, then enters a monastery. David is brought to London and is raised to be a beggar and thief until he is rescued by Dr. Roselli, an Italian political refugee, who raises David with his daughter Donna Roma. Years later David gets heavily involved in Italian politics and incurs the enmity of the corrupt Italian Prime Minister, which leads him to discover the hidden secrets of his family's past--and present.