Hidden artifice: Caravaggio and the case of the "Madonna of the Serpent."
Late in the year 1605, the papal Palafrenieri commissioned Caravaggio to paint the Madonna of the Serpent as a devotional image for an altar that they hoped to obtain in New St. Peter's. The work was installed in the church for less than a month before officials of St. Peter's ordered its removal
Thesis, Dissertation, English, 1998