The Symbol XP

The christogram has to be considered to be the symbol of (christian-) armed authority. It consists of the monogram of the greek letters  X (chi) and P (rho), the first letters of ‘Christ’. It is supposed to date from the very beginning of christianity but it received a more official meaning at the beginning of the 4th century when it was used by Constantine the Great as a symbol of his army. [1] In many cases the letters A and  ω, the first and last letters of the greek alphabet, are added to the cypher.

The  immediate cause for the adoption of the christogram is said to have been the vision of Constantine before the battle at the Milvian Bridge in 312.

The symbol is described by Lactantius (†320) as transversa X littera, summo capite circumflexo but is usually a monogram of the letters X and P.

The quote of Lactantius reads:

“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 X, with a perpendicular line drawn through it and turned round thus at the top, being the cypher of CHRIST. Having this sign, his troops stood to arms. The enemies advanced, but without their emperor, and they crossed the bridge. The armies met, and fought with the utmost exertions of valour, and firmly maintained their ground. In the meantime a sedition arose at Rome, and Maxentius was reviled as one who had abandoned all concern for the safety of the commonweal; and suddenly, while he exhibited the Circensian games on the anniversary of his reign, the people cried with one voice, "Constantine cannot be overcome!" Dismayed at this, Maxentius burst from the assembly, and having called some senators together, ordered the Sibylline books to be searched.” [2]

In the battle of the Milvian Bridge the christogram seems to have been written on the shields of the soldiers of Constantine but soon Constantine gave it a wider use in the first place by decorating his helmet with it. Eusebius of Ceasarea (†339 ca) in his Vita Constantini, Book IX writes in Chapter 31 that:

(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.

The way it was displayed by Constantine  can be seen on this medallion:

Medallion of Constatine the Great, 315 ca.

On this medallion Constantine wears a helmet crested with peacocks’ feathers and a christogram within a circle in front. He also bears a shield decorated with the Capitoline Wolf, the symbol of Rome. The medallion is dated between 313 and 321 and is one of the oldest if not the very oldest representation of the cypher in a military context. [3]

The combination of the christogram and the Capitoline Wolf  means ‘Christian Roman Army’ and replaced the eagle-and-thunderbolt which meant ‘The Consular Roman Army’ on standards and cuirasses.

Christogram

From the Catacomb of S. Agnese 350 AD ca.

Coll. Museo Vaticano

In its most elementary form however the christogram means ‘The Christian Armed Authority’ and all additions are further definitions and restrictions.

Such a symbol of Christian Armed Authoriy for example is on a coin of the emperor of the western provinces  Magnentius (350-†353) with a large christogram. [4] Contemporary with this coin is a plaquette from Trier, the capital of Gaul, attached to a coffin. [5] The chistogram alone however is mainly known from grafitti on walls and  objects.

Christogram

on a coin of Magnentius, emperor in  Gaul only (350-353).

Christogram from Trier 358 AD

In this way a shield with a christogram means: ‘A soldier of the christian army’ and the standard with a christogram ‘a division of the chistian armed forces’.

Silver dish of Constantius II (*317- †361)

Constantius on horseback, his shield-bearer with a shield charged with the  XP-cypher

Hermitage Museum, St. Petersburg inv. n° 1820/79

Æ 24,8 cm. Weight 660 g. Acquired in 1892. Found in Kerch, 1891. [6]

Reconstruction of the shield of Constantius II

Labarum

The standard of Constantine the Great himself  and his successors is known as the Labarum. It is described by Eusebius of Caesarea in his “Life of Constantine”:

“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.”

Follis of Constantine the Great, 327 AD

Early representation of the labarum, the wreath missing. [7]

Others “similar to it” often show the christogram on the vexillum or the vexillum having other charges, the christogram on top of the staff.

The labarum was abandoned when the empire was divided into a western- and an eastern part.

Christogram and Wreath

There is an unterrupted series of christogram known from the rule of Constatine the Great until the end of the 6th century. They are on shield, metal plaquettes, are represented in mosaics and are carved on coffin. In some cases they can be connected with certain individuals, usually occupying a very high rank in the military hierarchy.

Badges of distinction like crowns can be attached to them. These are crowns set with jewels, crowns of leaves and diadems. 

Examples of crowns set with jewels are the shield of Constantius II as illustrated above. On the Pile of Arecadius the squires of Theodosius  II and Honorius also bear such shields. An other example  is the shield on the mosaics of the S. Vitale in Ravenna. The shield the warrior bears there is almost identical to the shield  of Constantius II. It is green with a golden christogram surrounded by a crown set with precious stones. Behind him is an other warrior bearing a shield Gules, a star Vert within a bordure Azure of the model that also can be seen on the Pile of Arcadius. The arrangement of the company reminds the one on the Pile of Arcadius and a kind of replica of it in colour. [8]

From this examples we may cnclude that the warriors of the highest rank, like the emperor himself and the caesares who held the highest commands, could surround the christogram with a crown set with precious  stones.

Besides a lot of christograms are on memorials and sarcophaguses of which the owners cannot be identified or are uncertain.

Christogram in the Mausoleum of  Galla Placidia,

Ravenna  ca. 450.

These memorials, taking into account their expensiveness, have certainly been destined for high ranking military officials. This makes it possible, added to the place where they were erected, to speculate about the who and what of the original owners. To mention is the mosaic in the mausoleum of Galla Placidia in Ravenna. Here a christogram is depicted on a blue background, surrounde by a red and blue crown of leaves. Because red was the color of the infantry and blue the color of the cavalry it can be possible that this was the symbol of the Magister Equitum et Peditum of the West.

A candidate is Constantine III, husband of Galla Placidia, Chief commander, master of the infantry and the cavalry of the Western-Roman Empire, vicar of Italia Annonaria (†421).

Such christograms, surrounded by a crown of leaves are known from all over the Roman Empire. See for example the tomb from St. Vincent (ill.).

Also from France is the example of a headscarf knotted behind. This probably is the mark of distinction of a lower military official, probably a dux of Aquitania II.

Tomb of St. Vincent in the Church of St. Vincent in Mas d’Agenais (Lot & Garonne, Fr.). 5th century A.D.

Tomb in the church of Moissac

 (Tarn & Garonne, Fr.). 4th century A.D.

Christogram and Supporters

Freeze on the southern side of the Column of Arcadius, once Constantinople, 403 AD.

Trinity College, Cambridge (After Grabar, 1971)

In the uppermost register we see some vexillae with a christogram, in the second shield with christograms and in the centre the achievement of the Roman Christian Army Staff.

A christogram on a clipeus and supporters makes the achievement of an army organisation, for example of the army staff. When the christogram is supported by angels the organisation is autonomous and has its mandate ‘from heaven’. This is also possible for the army staff of a chief commander as is indicated on the Pile of Arcadius as ilustrated above. In other cases, as illustrated below, the christogram is supported by peacocks which are the emblems of a prefect and this achievement would mean: The prefectural army (-organisation). [9]

Crowned christogram between two staurograms

and an achievement of a clipeus with a christogram supported by two peacocks.

Sarcophagus in the Sant´Apollinare in Classe in Ravenna. The inscription reads: HIC REQUIESCAT IN PACE THEODORVS VB ARCHIEPISCOPVS. [10]

XP achievement

on the “Tomb of Stilicho”, S. Ambrogio, Milan.

An identifiable christogram is on the socalled sarcophagus of Stilicho alias of Valentinian II (375- †392) in the S. Ambrogio in Milan. Here a christogram within a crown is supported by two birds most resembling a male and a female peacock. [11] This matches the clipeus on the same tomb representing Valentinan and his wife.

XP achievement

On a tomb in Ravenna

However, other supporters were possible like lambs or agnus dei which resulted in an achievement  probably meaning “the army of the believers”. The interpretation of these achievements is not made easier when the crowns are missing.

Other Combinations with the Christogram

Other combinations with a christogram are a christigram with an imago, a christogram with a latin cross and a christogram with a square cross.

The oldest example of a combination of a christogram and an imago is on a tomb in Ravenna showing a Jesus orans with a crhistogram behind his head. Two other examples are given below.

Mosaic from Hinton St. Mary (U.K.) 4th cent.

 (Royal Commission on Historical Monuments, England)

Golden christogram

charged with a red cross, charged with a bearded face.

Merovingian (460 - 751). (Paris, Cabinet des Medailles)

Silver plate.  Æ 61 cm

Kumuca (Korydalla). Byzantine, 6th cent.

Antalya Museum, 1020 

A second combination consists of a christigram and a square cross and is a combination of the symbols of the armed and administrative authority. This combination was found in Byzantine themas.

Imperial tomb, before 340

Musei Vaticani n° 171

A third combination consists of a latin cross and a christogram within a crown. This is the symbol of combined religious and armed authority. It can be found on 4th century tombs. [12]

Other Monograms

ÈP monogram

Mausoleum of Galla Placidia, Ravenna 5th century

IX monogram

Baptisterium, Ravenna

Jesus orans and St. Peter with …P staff

Shrine with biblical scenes

Thessaloniki (?), 2nd half 4th century. Chased silver 9,7 Î 12,4 Î 10 cm

Nea Herakleia excavations, 1966

Thessalonica, Archaeological Museum Inv. 10070

Besides the christogram other christian monograms appeared in the first centuries of christianity. These were a square cross and a rho, an I and a chi and a latin cross and a rho.  

Of these monograms the ÈP monogram was the emblem of a christian civil official.

The IX monogram developed into the emblem of an archbischop

The …P-monogram was the emblem of a bishop. It was the model for the staff of a bishop initially quite literally as can be seen in the example, but from the 10th century in the form of a crozier.

Crozier

In: Isidor of Sevilla: Etymologia. Einsiedeln, 970-980

Einsiedeln, Stiftbibliothek, Cod. 167 (140)

The Disappearance of the Christogram.

After the fall of te Roman Empire the Roman Armies disappeared from the West. The use of the  christogram however was continued by its successor states and many examples are known from the Vandal, Frankish and Visigotic kingdoms.

The christogram remained the emblem of the amed forces as long as these remained one of the institutions of the empire and a part of the state. In Byzantium such armed forces were soon replaced by an armed force strictly loyal to the emperor after the model of a Praetorian Guard or personal armed force of the ruler. The emblem of such a guard had been a thunderbolt and this emblem developed into the so-called fleur de lis which was employed as well by the Byzantine imperial guard as well as by the armed forces of many West-European rulers. As a result the christogram disappeared completely as a symbol of armed authority after the 11th-12th century, and was replaced almost everywhere by a thunderbolt/fleur de lis.