The True Cross is the name for physical remnants which, by a Christian tradition, are believed to be from the cross upon which Jesus was crucified.

According to post-Nicene historians such as Socrates Scholasticus, the Empress Helena, mother of Constantine, the first Christian Emperor of Rome, travelled to the Holy Land in 326–28, founding churches and establishing relief agencies for the poor. Historians Gelasius of Caesarea and Rufinus claimed that she discovered the hiding place of three crosses that were believed to be used at the crucifixion of Jesus and of two thieves, St. Dismas and Gestas, executed with him, and that a miracle revealed which of the three was the True Cross.