The Feast of the Cross or the Exaltation of the Holy Cross commemorates the cross used in the crucifixion of Jesus. It is celebrated on 14 September according to the Gregorian calendar or 27 September for those that follow the Julian calendar. It is the day that the True Cross of our Lord and Savior Jesus Christ was found by Saint Helen, the mother of Emperor Constantine of the Byzantine Empire.
In the twentieth year of his reign (326), Emperor Constantine sent his mother Saint Helen to Jerusalem to venerate the holy places and to find the site of the Holy Sepulchre and of the Holy Cross. She began to search along Golgotha where there was the ancient temple of the goddess Aphrodite. The temple was demolished, and diggings began. Saint Helen was led to the finding of the True Cross due to the aromatic plant that grew in the area, the basil. This is why basil is used in the church liturgy and when holy water is sprinkled over the congregation. The digging brought to light the other two crosses on which the two thieves were crucified along with Jesus.
As there were three crosses, Helen asked Patriarch Macarius to identify the True Cross. He did this by placing the cross over the body of a dying woman, who was resurrected. Saint Helen immediately built the Church of the Holy Sepulchre on Golgotha. Patriarch Macarius raised the True Cross and set it in the Church of the Holy Sepulchre, also known as the Church of the Resurrection. This fourth-century church in the Christian Quarter of the Old City of Jerusalem is also the seat of the Greek Orthodox Patriarchate of Jerusalem. It is considered the holiest site in Christianity and the most important pilgrimage site for Christians. The church contains both the site where Jesus was crucified at Calvary or Golgotha, and the location of the empty tomb where Jesus was buried and resurrected. The pilgrims form long lines waiting their turn to see these two sites within the church. On the day of this religious celebration basil is given to the congregation so that they can remember that the True Cross on which Jesus was crucified was found next to the basil plant.
In 613 the Persians overran Palestine plundering and destroying the holy places, taking with them the spoils of the True Cross. In Persia it was considered magical because of certain miracles that occurred. On 14 September 629, Emperor Herakles, after the final victory over the Persians, reclaimed the Holy symbol of Christianity. It was taken first to Constantinople, but later returned to Jerusalem to the Church of the Holy Sepulchre as it is considered to belong to all of Christianity.
On the Cross of the Lord, there was also a small plaque with the inscription “INBI” (Jesus of Nazareth, King of the Jews), which Pontius Pilate had placed.