True Cross
Empress Helena (c.250–c.330 AD) was the mother of Constantine, the first Christian Emperor of Rome. Christianity was legalised through the Roman Empire in 312. According to the early writers, like Socrates Scolaticus,  Helena travelled to the Holy Land, founding churches and establishing relief agencies for the poor. She is said to have discovered the resting place  of the three crosses used at the crucifixion of Jesus and the two thieves - Dismas and Gestas - who were executed with him. Through a miracle it was revealed which of the three was the True Cross.