12 May – Saint Nereus and Saint Achilleus

Modern Hagiography

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.

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

La vie des saints

Medieval Hagiography

BHL, Supplement

Acta Sanctorum

The Cult of Saints in Late Antiquity Database

Pope Damasus’s Epitaph

“Nereus and Achilleus the martyrs joined the army and carried out the cruel orders of the tyrant, obeying his will continually out of fear. Then came a miracle of faith. They suddenly gave up their savagery, they were converted, they fled the camp of their evil leader, throwing away their shields, armor, and bloody spears. Professing the faith of Christ, they are happy to witness to its triumph. From these words of Damasus understand what great deeds can be brought about by Christ’s glory.” (quoted many places, searching for the source)

The Golden Legend (and illustrations)

Breviarium RomanumLatin & English.

Art & Architecture

Index of Medieval Art – Saint Nereus & Saint Achilleus

Catalogo generale dei beni culturali

BeWeB

Portail Biblissima

POP : la plateforme ouverte du patrimoine

Warburg Institute Iconographic Database

Vatican Colonnade – Nereus & Achilleus

The church of Santi Nereo e Achilleo in Rome

Rubens, Saint Domitilla with Saints Nereus and Achilleus

Post-Biblical Saints Art Index
Saints and their Attributes

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.

12 May – Saint Epiphanius of Salamis

By Giuseppe Franchi in the Bibliotheca Ambrosiana
Annus Dierum Sanctorum
Munera tua tibi sint, et dona domus tuae alteri da.
Thy rewards be to thyself, and the gifts of thy house give to another.
Daniel 5.17
Christus me docuit his non egere

Modern Hagiography

Roman Martyrology

Sanctorale Catholicum

Lives of the Saints by Alban Butler.

Lives of the Saints by Sabine Baring-Gould.

Character Calendar 

Pictorial Lives of the Saints 

La vie des saints 

Medieval Hagiography

BHL

Acta Sanctorum

Writings by Saint Epiphanius

Documenta Catholica Omnia

Prayer to the Blessed Virgin

On Weights and Measures

Letter from Epiphanius to John, Bishop of Jerusalem

Selections from the Panarion

Book 1 of the Panarion

Art & Architecture

Index of Medieval Art

Portail Biblissima

Warburg Institute Iconographic Database

Lives and Legends of the Great Hermits and Fathers of the Church, with Other Contemporary Saints by Mrs. Arthur Bell.

Emblems of Saints by Which They Are Distinguished in Works of Art by F. C. Husenbeth.

11 May – Saint Mamertus of Vienne

Modern Hagiography

Roman Martyrology

Sanctorale Catholicum

Lives of the Saints by Alban Butler.

Lives of the Saints by Sabine Baring-Gould.

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.

La vie des saints

Medieval Hagiography

BHL, Supplement

Acta Sanctorum

The Cult of Saints in Late Antiquity Database

Letter from Sidonius Apollinaris about Bishop Mamertus instituting Rogation Days (scroll down to letter XIV)

Art & Architecture

Portail Biblissima

Wikimedia Commons

Saints and their Attributes
Saints and their Attributes

Music

Cantus: A Database for Latin Ecclesiastical Chant

Customs & Traditions

Ice Saints