The Labarum shown above is that of the Order of Centurions is copyrighted, all rights reserved. The shield with the Chi Rho is in the Public Domain and was taken from a mosaic of Justinian the Just
IN HOC SIGNO VINCES
"By this Sign, Conquer"
VICTORY AT SAXA RUBA
"Labarum, hoc est Christi sacratum nomine signum."
Almighty God, Captain of the Host, grant, we beseech thee, that through thy grace we might be ever vigilant to recognize thy sign, and hear thy calling; through thy Son, our Lord Jesus Christ, who liveth and reigneth with thee and the Holy Ghost, one God, forever and ever. Amen
Ephesians 6: 10-18Psalm CXLIV
Finally, my brethren, be strong in the Lord, and in the power of his might. Put on the whole armour of God, that ye may be able to stand against the wiles of the devil. For we wrestle not against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this world, against spiritual wickedness in high places. Wherefore take unto you the whole armour of God, that ye may be able to withstand in the evil day, and having done all, to stand. Stand therefore, having your loins girt about with truth, and having on the breastplate of righteousness; And your feet shod with the preparation of the gospel of peace; Above all, taking the shield of faith, wherewith ye shall be able to quench all the fiery darts of the wicked. And take the helmet of salvation, and the sword of the Spirit, which is the word of God: Praying always with all prayer and supplication in the Spirit, and watching thereunto with all perseverance and supplication for all saints;
Luke xii. 35
Let your loins be girded about, and your lights burning; And ye yourselves like unto men that wait for their lord, when he will return from the wedding; that when he cometh and knocketh, they may open unto him immediately. Blessed are those servants, whom the lord when he cometh shall find watching: verily I say unto you, that he shall gird himself, and make them to sit down to meat, and will come forth and serve them. And if he shall come in the second watch, or come in the third watch, and find them so, blessed are those servants. And this know, that if the goodman of the house had known what hour the thief would come, he would have watched, and not have suffered his house to be broken through. Be ye therefore ready also: for the Son of man cometh at an hour when ye think not.
I commend the extracts from these histories: Lactantius and Eusebius. Lactantius wrote a few years after the Battle of Saxa Ruba. I recall that Lactantius was a member of the court and tutor to the children of Constantine. Eucebius was Constantine's court bishop, and wrote a biography after Constantine's death By tradition the Labarum was ordered to be carried before the Legions of Constantine after he had a vision, on 27 October 312, in the heavens of a "cross of light" and the Greek words TOUTO NIKA (conquer by this) and a subsequent encounter with the Lord Jesus Christ who told him to be at peace and conquer under his sign and to paint the sign on legionaires’ shields.
Constantine directed that a spear be covered in gold with a crosspiece representing a cross, and that the image of the chi-rho, the first two Greek initials in the name Christ, be placed above the crosspiece encircled by a crown/wreath. A banner was to hang from the crosspiece bearing the words of Christ in gold on a purple (red) and gold cloth. Constantine had this Labarum carried before his legions as he defeated a much larger pagan force under another emperor (Maxentius) at Milvian Bridge on 28 October. He ordered his men to place the chi-rho on their shields and he wore it on his helmet. Later in Rome, on the Triumph Arch for this victory, he credited divine intervention for his overwhelming victory of a force four to ten times the size of his.
Constantine disbanded the infamous Praetorian Guard, which formed the significant part of Maxentius's force. It had been responsible for so much intrigue, corruption, and imperial murders. He continued his policy begun in 306 in Gaul and Britain of lifting restrictions on Christianity as he occupied various portions of the Empire. In 323 when he had finally secured the entire Empire, he removed all restrictions and legalized the Christianity everywhere becoming its patron. Two years later he called the historic Council of Nicea where he moderated the discussion to try to bring unity to the Church.