Norfolk, Holkham Hall, MS 142
From Clavis Canonum
Norfolk, Holkham Hall, MS 142, written in Florence ca. 1464, contains 42 letters of Leo I, sermons of Leo, and other decretals. Related to Bernkastel-Kues, Bibliothek des St. Nikolaus-Hospitals, 39 according to Hoskin, Letters p. 386 as both contain a peculiar version of the Leonine letters drawn ultimately from the Collectio Dionysiana adaucta.