How he ordered the Erection of a Church at Jerusalem, in the Holy Place of our Saviour's Resurrection
After these things, the pious emperor addressed himself to another work truly worthy of record, in the province of Palestine. What then was this work? He judged it incumbent on him to render the blessed locality of our Saviour's resurrection an object of attraction and veneration to all. He issued immediate injunctions, therefore, for the erection in that spot of a house of prayer: and this he did, not on the mere natural impulse of his own mind, but being moved in spirit by the Saviour himself.
Source: Life of Constantine (New Advent)