Modern Hagiography
Lives of the Saints by Alban Butler.
Lives of the Saints by Francis Weninger.
Lives of the Saints by Sabine Baring-Gould.
Victories of the Martyrs by Saint Alphonsus Liguori.
The Lives of Saints, with Other Feasts of the Year, According to the Roman Calendar by Peter Ribadeneira.
Medieval Hagiography
The Cult of Saints in Late Antiquity Database
Prudentius, Peristephanon (?)
The Golden Legend (and illustrations)
Breviarium Romanum – Latin.
Art & Architecture
Index of Medieval Art – Hippolytus & Concordia
Catalogo generale dei beni culturali (filtering needed)
POP : la plateforme ouverte du patrimoine
Warburg Institute Iconographic Database
Guide to Christian Iconography: Images, Symbols, and Texts
Iglesia de San Hipólito el Real (Támara de Campos)
Post-Biblical Saints Art Index
Sacred and Legendary Art volume II by Mrs. Jameson.
A Handbook of Christian Symbols and Stories of the Saints as Illustrated in Art by Clara Erskine Clement.
Saints and their Symbols: A Companion in the Churches and Picture Galleries of Europe by E. A. Greene.
The Saints in Art by Joseph Maria von Radowitz.
Emblems of Saints by Which They Are Distinguished in Works of Art by F. C. Husenbeth.
Music
Nihil sub sole novum 