How Constantius his Father, being reproached with Poverty by Diocletian, filled his Treasury, and afterwards restored the Money to those by whom it had been contributed
In consequence of the many reports in circulation respecting this prince, describing his kindness and gentleness of character, and the extraordinary elevation of his piety, alleging too, that by reason of his extreme indulgence to his subjects, he had not even a supply of money laid up in his treasury; the emperor who at that time occupied the place of supreme power sent to reprehend his neglect of the public good, at the same time reproaching him with poverty, and alleging in proof of the charge the empty state of his treasury. On this he desired the messengers of the emperor to remain with him awhile, and, calling together the wealthiest of his subjects of all nations under his dominion, he informed them that he was in want of money, and that this was the time for them all to give a voluntary proof of their affection for their prince.
As soon as they heard this (as though they had long been desirous of an opportunity for showing the sincerity of their good will), with zealous alacrity they filled the treasury with gold and silver and other wealth; each eager to surpass the rest in the amount of his contribution: and this they did with cheerful and joyous countenances. And now Constantius desired the messengers of the great emperor personally to inspect his treasures, and directed them to give a faithful report of what they had seen; adding, that on the present occasion he had taken this money into his own hands, but that it had long been kept for his use in the custody of the owners, as securely as if under the charge of faithful treasurers. The ambassadors were overwhelmed with astonishment at what they had witnessed: and on their departure it is said that the truly generous prince sent for the owners of the property, and, after commending them severally for their obedience and true loyalty, restored it all, and bade them return to their homes.
This one circumstance, then, conveys a proof of the generosity of him whose character we are attempting to illustrate: another will contain the clearest testimony to his piety.
Source: Life of Constantine (New Advent)