The True Cross is the name for physical remnants traditionally believed to be from the cross upon which Jesus was crucified.
According to a number of early writers, the Empress Helena, (c.250–c.330 AD), mother of Constantine, the first Christian Emperor of Rome, at a date after 312 AD when Christianity was legalised throughout the Empire, travelled to the Holy Land, founding churches and establishing relief agencies for the poor. It was at this time that she discovered the hiding place of three crosses used at the crucifixion of Jesus and the two thieves that were executed with him. By a miracle it was revealed which of the three was the True Cross.
Many churches possess fragmentary remains which are by tradition alleged to be those of the True Cross. Their authenticity is not accepted universally by those of the Christian faith and the accuracy of the reports surrounding the discovery of the True Cross is questioned by many Christians. The acceptance and belief of that part of the tradition that pertains to the Early Christian Church is generally restricted to the Catholic and Orthodox Churches. The Medieval legend of its provenance in the Tree of Life is given less credence.
For detailed information regarding the Crucifixion itself, see Crucifixion of Jesus.

Provenance of the True Cross in "The Golden Legend"
In the late Middle Ages and Early Renaissance, there was a wide general acceptance of the origin of the True Cross and its history preceding the Crucifixion, as recorded by Voragine. This general acceptance is confirmed by the numerous artworks that depict this subject, culminating in one of the most famous fresco cycles of the Renaissance, the Legend of the True Cross by Piero della Francesca, painted on the walls of the chancel of the Church of San Francesco in Arezzo between 1452 and 1466, in which he reproduces faithfully the traditional episodes of the story as recorded in The Golden Legend.
It is worth noting that The Golden Legend and many of its sources had neither acceptance nor parallel in the Greek- or Syriac-speaking worlds. The above pre-Crucifixion history, therefore, is not to be found in Eastern Christianity.

Acceptance of this tradition

Finding the True Cross
Eusebius describes in his Life of Constantine how the site of the Holy Sepulchre, originally a site of veneration for the Christian community in Jerusalem, had been covered with earth and a temple of Venus had been built on top — although Eusebius does not say as much, this would probably have been done as part of Hadrian's reconstruction of Jerusalem as Aelia Capitolina in 135, following the destruction during the Jewish Revolt of 70 and Bar Kokhba's revolt of 132–135. Following his conversion to Christianity, Emperor Constantine ordered in about 325–326 that the site be uncovered and instructed Saint Macarius, Bishop of Jerusalem, to build a church on the site. In this Life, Eusebius does not mention the finding of the True Cross.

According to Eusebius
Socrates Scholasticus (born c. 380), in his Ecclesiastical History, gives a full description of the discovery [6] that was repeated later by Sozomen and by Theodoret. In it he describes how Saint Helena, Constantine's aged mother, had the temple destroyed and the Sepulchre uncovered, whereupon three crosses and the titulus from Jesus's crucifixion were uncovered as well. In Socrates's version of the story, Macarius had the three crosses placed in turn on a deathly ill woman. This woman recovered at the touch of the third cross, which was taken as a sign that this was the cross of Christ, the new Christian symbol. Socrates also reports that, having also found the nails with which Christ had been fastened to the cross, Helena sent these to Constantinople, where they were incorporated into the emperor's helmet and the bridle of his horse.

According to Socrates Scolasticus
Sozomen (died c. 450), in his Ecclesiastical History [7], gives essentially the same version as Socrates. He also adds that it was said (by whom he does not say) that the location of the Sepulchre was "disclosed by a Hebrew who dwelt in the East, and who derived his information from some documents which had come to him by paternal inheritance" (although Sozomen himself disputes this account) and that a dead person was also revived by the touch of the Cross. Later popular versions of this story state that the Jew who assisted Helena was named Jude or Judas, but later converted to Christianity and took the name Kyriakos.

According to Sozomen
Theodoret (died c. 457) in his Ecclesiastical History Chapter xvii gives what had become the standard version of the finding of the True Cross:
When the empress beheld the place where the Saviour suffered, she immediately ordered the idolatrous temple, which had been there erected, to be destroyed, and the very earth on which it stood to be removed. When the tomb, which had been so long concealed, was discovered, three crosses were seen buried near the Lord's sepulchre. All held it as certain that one of these crosses was that of our Lord Jesus Christ, and that the other two were those of the thieves who were crucified with Him. Yet they could not discern to which of the three the Body of the Lord had been brought nigh, and which had received the outpouring of His precious Blood. But the wise and holy Macarius, the president of the city, resolved this question in the following manner. He caused a lady of rank, who had been long suffering from disease, to be touched by each of the crosses, with earnest prayer, and thus discerned the virtue residing in that of the Saviour. For the instant this cross was brought near the lady, it expelled the sore disease, and made her whole.
With the Cross were also found the Holy Nails, which Helena took with her back to Constantinople. According to Theodoret, "She had part of the cross of our Saviour conveyed to the palace. The rest was enclosed in a covering of silver, and committed to the care of the bishop of the city, whom she exhorted to preserve it carefully, in order that it might be transmitted uninjured to posterity."
Another popular ancient version from the Syriac tradition replaced Helena with a fictitious first-century empress named Protonike.
Historians consider these versions to be apocryphal in varying degrees. It is certain, however, that the Basilica of the Holy Sepulchre was completed by 335 and that alleged relics of the Cross were being venerated there by the 340s, as they are mentioned in the Catecheses of Cyril of Jerusalem (see below).

According to Theodoret
The silver reliquary that was left at the Basilica of the Holy Sepulchre in care of the bishop of Jerusalem was exhibited periodically to the faithful. In the 380s a nun named Egeria who was travelling on pilgrimage described the veneration of the True Cross at Jerusalem in a long letter, the Itinerario Egeriae that she sent back to her community of women:
Then a chair is placed for the bishop in Golgotha behind the [liturgical] Cross, which is now standing; the bishop duly takes his seat in the chair, and a table covered with a linen cloth is placed before him; the deacons stand round the table, and a silver-gilt casket is brought in which is the holy wood of the Cross. The casket is opened and [the wood] is taken out, and both the wood of the Cross and the title are placed upon the table. Now, when it has been put upon the table, the bishop, as he sits, holds the extremities of the sacred wood firmly in his hands, while the deacons who stand around guard it. It is guarded thus because the custom is that the people, both faithful and catechumens, come one by one and, bowing down at the table, kiss the sacred wood and pass through. And because, I know not when, some one is said to have bitten off and stolen a portion of the sacred wood, it is thus guarded by the deacons who stand around, lest any one approaching should venture to do so again. And as all the people pass by one by one, all bowing themselves, they touch the Cross and the title, first with their foreheads and then with their eyes; then they kiss the Cross and pass through, but none lays his hand upon it to touch it. When they have kissed the Cross and have passed through, a deacon stands holding the ring of Solomon and the horn from which the kings were anointed; they kiss the horn also and gaze at the ring…
Before long, but perhaps not until after the visit of Egeria, it was possible also to venerate the crown of thorns, the pillar at which Christ was scourged, and the lance that pierced his side.
In 614 the Sassanid Emperor Khosrau II ("Chosroes") removed the part of the cross as a trophy, when he captured Jerusalem. Thirteen years later, in 628, the Byzantine Emperor Heraclius defeated Khosrau and retook the relic, which he at first placed in Constantinople, and later took back to Jerusalem in March 21, 630. [8] Around 1009, Christians in Jerusalem hid the part of the cross and it remained hidden until it was rediscovered during the First Crusade, on August 5, 1099, by Arnulf Malecorne, the first Latin Patriarch of Jerusalem, conveniently at a moment when a morale boost was needed. The relic that Arnulf discovered was a small fragment of wood embedded in a golden cross, and it became the most sacred relic of the Latin Kingdom of Jerusalem, with none of the controversy that had followed their discovery of the Holy Lance in Antioch. It was housed in the Church of the Holy Sepulchre under the protection of the Latin Patriarch, who marched with it ahead of the army before every battle. It was captured by Saladin during the Battle of Hattin in 1187 and subsequently disappeared.
Other fragments of the Cross were further broken up, and the pieces were widely distributed; in 348, in one of his Catecheses, Cyril of Jerusalem remarked that the "whole earth is full of the relics of the Cross of Christ," . However, although it is possible, the poem need not be referring to this specific relic or have this incident as the reason for its composition.

Dispersal of relics of the True Cross
St John Chrysostom wrote homilies on the three crosses:
Kings removing their diadems take up the cross, the symbol of their Saviour's death; on the purple, the cross; in their prayers, the cross; on their armour, the cross; on the holy table, the cross; throughout the universe, the cross. The cross shines brighter than the sun.
The Roman Catholic Church, many Protestant denominations (most notably those with Anglican origins), and the Eastern Orthodox churches celebrate the Feast of the Exaltation of the Cross on September 14, the anniversary of the dedication of the Church of the Holy Sepulchre. In later centuries, these celebrations also included commemoration of the rescue of the True Cross from the Persians in 628. In the Gallician usage, beginning about the seventh century, the Feast of the Cross was celebrated on May 3. According to the Catholic Encyclopedia, when the Gallician and Roman practices were combined, the September date, for which the Vatican adopted the official name "Triumph of the Cross" in 1963, was used to commemorate the rescue from the Persians and the May date was kept as the "Invention of the True Cross" to commemorate the finding. The September date is often referred to in the West as Holy Cross Day; the May date was dropped from the liturgical calendar by the Second Vatican Council in 1970. (See also Roodmas.) The Orthodox still commemorate both events on September 14, one of the twelve Great Feasts of the liturgical year, and the 'Procession of the Venerable Wood of the Cross' on 1 August, the day on which the relics of the True Cross would be carried through the streets of Constantinople to bless the city [10].
In addition to celebrations on fixed days, there are certain days of the variable cycle when the Cross is celebrated. The Roman Catholic Church has a formal 'Adoration of the Cross' (the term is inaccurate, but sanctioned by long use[11]) during the services for Good Friday, while the Orthodox celebrate an additional Veneration of the Cross on the third Sunday of Great Lent. In Greek Orthodox churches everywhere, a replica of the cross is brought out in procession on Holy Thursday for the people to venerate.

Veneration of the Cross

Crucifixion
Battle of Hattin
Relic
Christian cross
Île de la Cité
Jesus
Stavelot Triptych
Meskel
Titulus Crucis
Santa Croce in Gerusalemme Bibliography