In 1770 the French historian Charles Le Beau (1701-1778) wrote in The History of the Lower Empire about the contribution of Constantine the Great:
The Emperor consulted Christianity on the measures he took for its advancement, and he employed no methods but such as it approved.
He distinguished those who professed it, by favours; he took pains to reduce paganism to contempt and oblivion, by shutting up, dishonouring, demolishing the temples, stripping them of their riches, laying open the artifices of the idolatrous Priests, and prohibiting sacrifices, as far as he might without violence, and without endangering the character of father of all his subjects, even of those, who remained in error.
Where he could not abolish superstition, he suppressed the disorders at least, which were the consequence of it.
He made severe laws to restrain those horrible excesses, which nature disclaims.
He preached Jesus Christ himself by his piety, his example, his conferences with the deputies of Infidel nations, and the letters which he wrote to the Barbarians.
Far from paying to the Heathen gods the honour of placing his statue in their temples, as Socrates falsely asserts, he forbad that abuse, according to Eusebius, by an express law.
Bishops he held in great veneration; and established them in many places.
He rendered the exterior form of worship august and magnificent.
He set up in every part the salutary sign of the cross: every gate and every wall of his palaces exhibited that image.
His coins no longer bore inscriptions expressive of superstition: he was represented on them with his face lifted up towards heaven, and his hands extended in the posture of a suppliant.
But he did not abandon himself to a headlong zeal; he chose to refer to time, circumstances, and above all to divine grace, the completion of God's work.
Temples were still remaining at Rome, Alexandria, Antioch, Gaza, Apamea, and in several other places, where the destruction of them would have been attended with fatal consequences.
We have a law, which was posted up at Carthage the day before his death, confirming the privileges of the Priests in Africa.
It was reserved to Theodosius to give the final stroke.
Humanity and religion itself are indebted to Constantine for not having given martyrs to idolatry.