In the medieval heraldic system of symbols, state and state symbols do not play a prominent role, but are almost absent. This has to do with the fact that the empire and state, after the division in 395 and the (partial) disintegration of the Roman Empire, were thought to belong to the political system of the Roman Empire, which was  no longer a reality in its original Constantine form. This part of the political organization was included in Christian religious symbolism in which Christ is represented as the world ruler uniting the legislative and executive power. For this reason, he is often depicted together with a sun and a moon, a constellation that we find, as we know, also with the Chinese emperors.

Instead of the sun and the moon that play an important role in the older systems, the symbols of  the ranges of authority play a major role in the christian heraldic system. These are derived from the symbols that were previously developed by Emperor Constantine the Great (307-337) in the Roman Empire.

The main sources informing us about the realization of these symbols are the writings of Lactantius, the house teacher of Crispus, the eldest son of Constantine, and the biography of Constantine written by Eusebius of Caesarea at the end of Constantine's life. Especially the last writer has caused many problems of interpretation. [1] Therefore, before I go to treat these symbols, I will copy the text of the relevant passages translated into English.

Lactantius († 320) writes:  [2]

44. 5-6 Constantine was directed in a dream to cause the heavenly sign to be delineated on the shields of his soldiers, and so to proceed to battle. He did as he had been commanded, and he marked on their shields the letter Χ, with a perpendicular line drawn through it and turned round thus at the top, being the cipher of CHRIST. Having this sign (ΧР), his troops stood to arms. [3]

Eusebius (†339) writes:

CHAPTER XXVIII: How, while he was praying, God sent him a Vision of a Cross of Light in the Heavens at Mid-day, with an Inscription admonishing him to conquer by that.

ACCORDINGLY he called on him with earnest prayer and supplications that he would reveal to him who he was, and stretch forth his right hand to help him in his present difficulties. And while he was thus praying with fervent entreaty, a most marvelous sign appeared to him from heaven, the account of which it might have been hard to believe had it been related by any other person. But since the victorious emperor himself long afterwards declared it to the writer of this history, (1) when he was honored with his acquaintance and society, and confirmed his statement by an oath, who could hesitate to accredit the relation, especially since the testimony of after- time has established its truth? He said that about noon, when the day was already beginning to decline, he saw with his own eyes the trophy of a cross of light in the heavens, above the sun, and bearing the inscription, CONQUER BY THIS. At this sight he himself was struck with amazement, and his whole army also, which followed him on this expedition, and witnessed the miracle. (2)

CHAPTER XXIX: How the Christ of God appeared to him in his Sleep, and commanded him to use in his Wars a Standard made in the Form of the Cross.

He said, moreover, that he doubted within himself what the import of this apparition could be. And while he continued to ponder and reason on its meaning, night suddenly came on; then in his sleep the Christ of God appeared to him with the same sign which he had seen in the heavens, and commanded him to make a likeness of that sign which he had seen in the heavens, and to use it as a safeguard in all engagements with his enemies.

CHAPTER XXX: The Making of the Standard of the Cross.

AT dawn of day he arose, and communicated the marvel to his friends: and then, calling together the workers in gold and precious stones, he sat in the midst of them, and described to them the figure of the sign he had seen, bidding them represent it in gold and precious stones. And this representation I myself have had an opportunity of seeing.

CHAPTER XXXI: A Description of the Standard of the Cross, which the Romans now call the Labarum. (1)

Now it was made in the following manner. A long spear, overlaid with gold, formed the figure of the cross by means of a transverse bar laid over it. On the top of the whole was fixed a wreath of gold and precious stones; and within this, (2) the symbol of the Saviour's name, two letters indicating the name of Christ by means of its initial characters, the letter P being intersected by X in its centre: (3) and these letters the emperor was in the habit of wearing on his helmet at a later period. From the cross-bar of the spear was suspended a cloth, (4) a royal piece, covered with a profuse embroidery of most brilliant precious stones; and which, being also richly interlaced with gold, presented an indescribable degree of beauty to the beholder. This banner was of a square form, and the upright staff, whose lower section was of great length,(5) bore a golden half-length portrait (6) of the pious emperor and his children on its upper part, beneath the trophy of the cross, and immediately above the embroidered banner.

The emperor constantly made use of this sign of salvation as a safeguard against every adverse and hostile power, and commanded that others similar to it should be carried at the head of all his armies. [4]

In order to be able to understand the passages properly, we absolutely need more data and these can be extracted from other sources, among other things from the numistatics. It then appears that Eusebius describes the symbols that were in use at the end of Constantine's life, namely the crux quadrata or Greek cross (described in 28 (2)), the christogram XP on top of a latin cross (described in 31). (1)) and the labarum (without transition described in 31 (2)). Lactantius thus describes another symbol, namely the ÇP staurogram. [5]

The Christianization of  state symbolism was not immediately adopted by Constantine, as evidenced by this passage by Eusebius dating only from the end of the life of Constatine. The “Christian Myth” [6] was subsequently adapted, partly by the church fathers, to the actual administrative structure of the Empire as it existed since Diocletian. This development ended with the acceptance of the idea of ​​the Holy Trinity or the homoousios at the 1st Council of Constantinople in 381. The doctrine was endorsed by Emperor Theodosius I, who was a great proponent of it. From this time on, God, Christ and the Holy Spirit were supposed to be manifestations of the same Supreme Being, a thought that can be understood in terms of the terms but which otherwise presents problems as it is difficult to see how one can be three and vice versa. [7] The emperor's place was occupied by Christ himself in the church. The four prefects found a parallel in the four evangelists John, Mark, Luke and Matthew [8] and the twelve vicars at the head of the dioceses in the twelve disciples. In this way it was sometimes difficult to distinguish an image of the emperor with his senior officials from an image of Christ with his disciples.

The Christian institutional symbols were further elaborated by the successors of Constantine and in particular by Emperor Theodosius I. This can be seen on the so-called Column of Arcadius. (from the year 403). On this are the symbols of the three sections in which the organization of the Roman Empire at that time was divided or deemed to be divided. The structure of the eastern part of the Christian Roman Empire is briefly displayed on the Column. This consists of three segments or authority areas. At the head of each segment are the emperor and his fellow emperor.

• The Column of Arcadius in Constantinople. [9]

d The Column of Arcadius was founded in 403 at the Forum of Arcadius in Constantinople. It was demolished in 1729 but drawings were made in the 16th century  Freshfield Album. These are kept at Trinity College in Cambridge.

There are carved friezes on the base on three sides. In the fourth side was the door to the column. The sides are dedicated to the administration, the army and the church.

Column of Arcadius, East side

Trinity College, Cambridge (after Grabar)

• On the east side is a rectangular frame with a crux quadrata between two warriors. If the two emperors Arcadius and Theodius II are meant with these warriors, then the administrative symbol is united with the image and this combination stands in the tradition of previous images. The symbol is held by two angels.

In the second register are two dignitaries in toga with their shield-bearers, their shields ensigned with christograms

The third register presumably includes the six prefects the governors of the six officials of the six prefectures pretorio (Rome, Gallia, Italia and Constantinopel, Illyricum and Orient). On either side of them, under a ciborium, the personifications of Rome and Constantinople.

The fourth register is reserved for the weaponry of the Magister Officiorum [10]

Column of Arcadius, South side

Trinity College, Cambridge (after Grabar)

• The south side begins (for technical reasons) with the second register. On this is a christogram between an A and a Ѡ, surrounded by a laurel crown and supported by two angels. On both sides are  cuirasses, helmets and shields of which two with a christogram.

In the third register are the two emperors in armor with a staff and a Victoria in hand. (see the diptychon of Probus from the Cathedral of Aosta with a picture of Honorius). They have two kneeling prisoners between them. On either side of them are dignitaries, presumably the magistri militum, but the number of these does not match those mentioned in the Notitia Dignitatum. [11]

The fourth register would contain the personifications or commanders (duces) of the provinces.

The first register is finally dedicated to the Magister Officiorum.

Column of Arcadius, West side

Trinity College, Cambridge (after Grabar)

• On the west side is a latin cross within a laurel wreath, supported by two angels. On either side two four-in-hands (quadriga's)  possibly representing the marks of honour of the prefects of Rome and Constantinople.

In the second register are the two caesars, also this time in armor and with a long staff. If they have held something in their other hands, then that is gone. Behind them there are ecclesiastical dignitaries, which may be the patriarchs of Rome, Constantinople and Antioch. On either side are their bodyguards whose captains carry shields with a christogram between an A and an Ѡ. The others wear a shield with a daisy-shaped or sun-like decoration. The caesars are supposed to be represented here as "Defenders of the Faith". In the third register men are depicted in non-Roman (barbarian) costume, they are brought in by soldiers armed with spears, preceded by a Victoria, to pay tribute to a trophy consisting of a cross with a helmet, a cloak and two shields. At the foot of this trophy, two men are busy inscribing PAX on shields.

The fourth register depicts war-booty. [12]

Two of these institutional symbols: the square cross and the latin cross are quite common in the heraldic system. The christogram has disappeared completely and has been replaced by the thunderbolt and by the fleur de lys. These in their turn, have been replaced by the sword and the anchor which are figuring in the emblems of the armed forces of many modern countries.