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Secondary sourceBookafter 316

De mortibus persecutorum

Lactantius · after 316

A work by Lactantius describing the deaths of emperors who persecuted Christians, and the earliest account of Constantine's dream before the Battle of the Milvian Bridge.

Lactantius, tutor to Constantine's son, gives the earliest account of Constantine's vision before the Milvian Bridge and the Edict of Milan's text.

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Title page of a 1684 printed book: 'L. Caecilii Firmiani Lactantii, De mortibus persecutorum, liber; cum notis Johannis Columbi ad Gisbertum Cuperum', printed at Aboae by Johannes Winter in Finlandia. Below the text is a woodcut of a pelican-like bird with young on a branch, and a faded library stamp reading 'Bibl. Collegii ... Augsburg'.
Lactantius, De mortibus persecutorum, 1684 printed edition. Printed at Aboae by Johannes Winter, Finland.

About this source

What it is

De mortibus persecutorum (On the Deaths of the Persecutors) is a Latin work by Lactantius, a Christian scholar who served at the courts of both Diocletian and Constantine, written sometime after 316. It describes the downfall of emperors who persecuted Christians, mainly those of the Tetrarchy period.

Why it matters

The book contains the earliest surviving account of Constantine's dream before the Battle of the Milvian Bridge, in which he was told to mark his soldiers' shields with the chi-rho symbol, a key moment later linked to his conversion to Christianity. It is also one of the sources for the Edict of Milan. Lactantius wrote openly as a Christian apologist, aiming to show God punishing persecutors, so historians read it carefully for bias.

Look closer

  • Why does Lactantius's account of Constantine's dream differ from Eusebius's account of a vision in the sky?
  • What does Lactantius say was his purpose in writing, and how might that purpose shape what he included?
  • Why might a tutor to Constantine's own son have been inclined to present him favorably?

This book is part of the curated material that grounds the AI version of Constantine the Great on Humy.ai — when students ask about related events, the AI can quote it and cite it.

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Manuscript page of handwritten Greek text in brown ink on cream parchment, with a decorated red and gold initial letter at the left margin. A dark ink blot is visible in the middle of the text block. The script is a cursive Greek hand, and the page appears to be from a 16th-century codex.Document

Secondary source

Edict of Milan

Constantine the Great · 313 AD

Woodcut-style medallion portrait in profile of a man in a plumed helmet with a laurel wreath, holding a spear, with the inscription CONSTANTINVS MAX AVG around the rim. Above it a Roman-numeral heading and German text; below, German text and a monogram M 2 on a book page.Artifact

Secondary source

Woodcut Portrait of Constantine the Great

Josse van Gietleughen

Photo of the south-facing attic inscription on the Arch of Constantine in Rome: a large carved Latin inscription in two rows of capital letters on pale marble, flanked by two statues of captive or attendant figures, with a blue sky above.Artifact

Primary source

Arch of Constantine

Roman Senate · c. 312-315

Medieval illuminated manuscript page with four framed scenes in gold and blue panels. Bottom left shows a bishop with halo baptising a nude figure in a font of flames, while a crowned figure looks on. Other panels show standing saints and a scene of a figure with a torch.Painting

Secondary source

Constantine the Great Baptised by St Sylvester

c. 1200

Title page of a book reading 'Ecclesiastical History: The Life of the Blessed Emperor Constantine, in four books, from 306 to 337 A.D., by Eusebius Pamphilus', London, Samuel Bagster and Sons, 1845. Includes a library stamp and a publisher's ornament.Book

Secondary source

Life of Constantine

Eusebius of Caesarea · 345

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