Manuscripts in the UTL Collections, see Thomas Fisher Library.
Kornbluth Photography - Image Collection for educational uses.
Index of Medieval Art. Princeton University. Early apostolic times up to A.D. 1400. Many of the manuscripts in the Pierpont Morgan Library have been digitized and are part of this collection. (Princeton University) Licensed to UT students and faculty.
Islamic Art and Architecture Research Guide. University of Toronto Mississauga.
Medieval Kingdom of Sicily. Image Database.This website collects historic images of the medieval monuments and cities in the Kingdom of Sicily. This body of imagery is vast and spread among public and private collections, museums, archives and libraries in many different countries. As an ongoing project that expands as new images are found and catalogued, our collection of images will probably never be exhaustive or complete.
See also the following research guides:
Bible, Archaeology and Museum Collections, Medieval Manuscript Collections, Medieval Studies, Islamic Art and Architecture.
FINDING PAPAL DOCUMENTS
See the Research Guide produced by Michael Stoller at New York University Library.