The Standard Called the Labarum

It was made in the following way. A long spear, overlaid with gold, formed the shape of the cross by means of a crossbar laid over it. On top of the whole was fixed a wreath of gold and precious stones, and within it was the symbol of the Savior’s name: two letters showing the name of Christ by its first characters, the letter P crossed by X at its center. The emperor was in the habit of wearing these letters on his helmet at a later time. From the crossbar of the spear hung a cloth, a royal piece, covered with a rich embroidery of the most brilliant precious stones, and also richly interwoven with gold, so that it was indescribably beautiful to look at. This banner was square. The upright staff, whose lower part was of great length, bore on its upper part, beneath the trophy of the cross and just above the embroidered banner, a golden half-length portrait of the godly emperor and his children. [a]

The emperor constantly used this sign of salvation as a safeguard against every opposing and hostile power, and commanded that others like it should be carried at the head of all his armies.