Represented here by their characteristic attributes are the four evangelists surrounding the Lamb of God (Agnus Dei), as derived from the vision of John in the Book of Revelation (4:6–7): an angel (Matthew), a winged lion (Mark), a winged ox (Luke), and an eagle (John). Originally this plaque would have covered a deluxe binding of a now-lost Gospel book. The stylization of the symbols and the type of interlaced foliate cross find parallels in manuscript illumination produced within the southern Italian region of Benevento, including at the famed Benedictine monastery of Monte Cassino.
J. Pierpont Morgan, London and New York (until 1917)
Ostoia, Vera K. The Middle Ages: Treasures from the Cloisters and the Metropolitan Museum of Art. Los Angeles: Los Angeles County Museum of Art, 1969. no. 36, pp. 82-83, 255.
Frazer, Margaret English. "Medieval Church Treasuries." The Metropolitan Museum of Art Bulletin, n.s., 43, no. 3 (Winter 1985-1986). p. 17, fig. 11.
Husband, Timothy B., and Charles T. Little. Europe in the Middle Ages. New York: The Metropolitan Museum of Art, 1987. no. 35, p. 44.
Fisher, Sally. The Square Halo and Other Mysteries of Western Art: Images and the Stories that Inspire Them. New York: Harry N. Abrams, 1995. p. 90.
Wixom, William D., and Margaret Lawson. "Picturing the Apocalypse: Illustrated Leaves from a Medieval Spanish Manuscript." The Metropolitan Museum of Art Bulletin, n.s., 59, no. 3 (Winter 2002). p. 5, fig. 1.
Galan y Galindo, Angel. Marfiles Medievales del Islam: Volume 1, Texto. Cordoba: Publicaciones Obra Social Y Cultural Cajasur, 2005. p. 278.
Wixom, William D. "Medieval Sculpture at the Metropolitan: 800 to 1400." The Metropolitan Museum of Art Bulletin, n.s., 62, no. 4 (2005). p. 8.
Pace, Valentino. "Aspetti dell'arte nella Campania Longobarda." In Arte medievale in Italia meridionale. Nuovo Medioevo, Vol. 70. Napoli, 2007. p. 13, fig. 19.
Galan y Galindo, Angel. "El marfil y el comercio medieval Mediterráneo." Arte, Arqueología e Historia 19 (2012). p. 42.
Crivello, Fabrizio. "Gli avori del gruppo di 'Amalfi/Salerno': Considerazioni sui presupposti, sulla cronologia e la localizzazione." In The Salerno Ivories: Objects, Histories, Contexts, edited by Francesca Dell’Acqua, Anthony Cutler, Herbert L. Kessler, Avinoam Shalem, and Dr. Gerhard Wolf. Berlin: Gebr. Mann Verlag, 2016. pp. 62–63, fig. 1.