I am told: "The fresco is to be found in the Chapel of the Madonna of Partorienti. It was painted by Giovan Ricci da Novara, between 1618 and 1619. The panel is one of several by da Novara, and represents 'The Longobard and the Key of St Peter', which is an episode narrated by Gregory the Great. The Longobard is the man committing suicide. He tried to break the golden key from St Peter's tomb and then, taken over by an evil spirit, he slit his own throat. The enthroned king is Autari, the king of the (Arian) Lombards, who repairs the damage done to St Peter's tomb. "