The Triumph of the Cross
When Christ's torn and bloodied Body was taken down from the Cross on Calvary, the Cross itself was taken and thrown into a ditch, and covered with dirt and rocks, so that the faithful could not venerate it, or even find it.
Almost three centuries later, Constantine the Great, while doing battle against Maxentius for the throne of the Roman Empire, prayed to God for aid in his battle.
As an answer to his prayer, a luminous Cross appeared in the heavens, inscribed "In this Sign you will conquer."
In gratitude for the victory against Maxentius, Constantine the Great had the sign of Christianity placed on the Roman standards, and on the shields of his soldiers.
Then came the finding of the True Cross by Saint Helena in the year 326.
In the year 614, Chosroes II, King of Persia, invaded Syria and Palestine. He sacked Jerusalem, carrying off many treasures, including the True Cross. Then the Emperor Heraclius of Constantinope, with a large army, invaded Persia and regained possession of the True Cross.
He brought it back to Jerusalem very reverently in 629, and when he reached the City gate that led to Calvary, the Emperor laid aside all his finery, and dressed in sackcloth, and barefoot, he carried the Cross up the hill of Calvary, and restored it to its proper place in the Church of the Holy Sepulchre.