AD 312

Constantine the Great and Christianity

Constantine begins open imperial patronage of Christianity

Constantine’s treasury order gave Caecilian of Carthage 3,000 folles — and told him to ask for more if that proved insufficient.

Weeks after taking Rome

In the immediate aftermath of Constantine’s October 312 victory at Rome, his allegiance to the Christian God became public, and work may have begun as early as November on the imperially sponsored Lateran basilica.

The project occupied barracks formerly used by Maxentius’s imperial horse guard, making Christian construction physically visible on property associated with the defeated regime.

Money, property, exemptions

During the winter of 312/313, Constantine ordered an imperial payment of 3,000 folles to Caecilian of Carthage for Catholic clergy across Roman Africa, with authorization for additional funds if necessary.

He also ordered church property restored and exempted clergy loyal to Caecilian from compulsory public duties, turning toleration into material and legal preference. His exemption letter argued that freeing clergy from civic labour benefited the Roman state, because their worship secured divine favour.

Patronage, not establishment

The resulting policy made the church a publicly recognized and imperially patronized institution. It did not make Christianity the empire’s official religion, and Constantine went on governing a religiously plural empire.

It is a policy transition rather than a securely dated proclamation. The first visible measures fall between late 312 and 313, the Lateran groundbreaking day is unknown, and several of the surviving administrative letters belong to the winter of 312/313 or to 313.

Sources

Researched 23 Aug 2026 5 sources 2 audit passes Date disputed

How this was checked

Researched from the web into a fact sheet, rewritten from that sheet, then audited against it by a different model. How the pipeline works →

Date disputed. Sources disagree; the research places it at ~0312.

What the sources leave uncertain

This is a policy transition, not a securely dated single proclamation. Its first visible measures fall between late 312 and 313.
The Lateran construction start is commonly placed after the October victory and possibly as early as November 312, but the precise groundbreaking day is unknown.
Whether 'conversion' means private belief, public allegiance, catechumenal status, or baptism produces different dates. Constantine's personal convictions cannot be verified as an event on one day in 312.
Several surviving administrative letters belong to the winter of 312/313 or to 313; generic accounts often compress them all into the battle year.