14 October – Saint Callixtus I

Modern Hagiography

Bibliotheca Sanctorum

Martyrologium Romanum

Roman Martyrology

Sanctorale Catholicum

Lives of the Saints by Alban Butler.

Lives of the Saints by Sabine Baring-Gould.

The Liturgical Year by Dom Guéranger.

Character Calendar

Pictorial Lives of the Saints

Our Birthday Bouquet Culled from the Shrines of the Saints and the Gardens of the Poets by Eleanor C. Donnelly.

Pictorial Half Hours with the Saints by Auguste François Lecanu.

Miniature Lives Of The Saints For Every Day In The Year by Henry Sebastian Bowden.

The Lives of Saints, with Other Feasts of the Year, According to the Roman Calendar by Peter Ribadeneira.

La vie des saints

Rome and the Negro:  Lives of the Noted African Bishops, Saints, Martyrs, Holy Women and Fathers of Deserts

Medieval Hagiography

BHL, Supplement

Acta Sanctorum

The Cult of Saints in Late Antiquity Database

Liber pontificalis

The Golden Legend (and illustrations)

Breviarium RomanumLatin & English.

Writings of Pope Callixtus I

Documenta Catholica Omnia

Art & Architecture

Index of Medieval Art

Portail Biblissima

Warburg Institute Iconographic Database

Medieval Religion Listserv – 2016 Dillon.

Catacombe di San CallistoOfficial Website, Roma sotterranea: Or Some Account of the Roman Catacombs, Especially of the Cemetery of San Callisto, The Catacombs of Saint Callistus: History and Description

Church of San Callisto in Rome

Sistine Chapel, North Wall

In situ
Die Sixtinische Kapelle
Sixth Portrait from the left, Sala del Trono in the Palazzo Vescovile di Todi
Post-Biblical Saints Art Index
Saints and their Attributes
Saints and their Emblems

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

Cantus: A Database for Latin Ecclesiastical Chant