The mother of Constantine the Great, St. Helena Empress lived from the middle of the third century to the beginning of the fourth. She became the wife or concubine (the records are unclear) of Constantius, Constantine’s father, while he was still a soldier; when Constantius became emperor, he divorced her in favor of a new bride of higher social station. But then, when Constantine succeeded Constantius, Constantine, who was always close to her, gave his mother the status of empress, bringing her back to the imperial court. 

Around A.D. 320, Helena–how this idea came to her remains unclear– went on a pilgrimage to Jerusalem to find the True Cross, the cross on which Christ was crucified. In Jerusalem she built two new churches, the Church of the Nativity in Bethlehem and a church on the Mount of Olives. And she returned to Europe with relics that included what she believed to be thorns from Christ’s crown of thorns, nails from the cross, and fragments of the True Cross itself.

From Evelyn Waugh’s article about her:

We have no absolute certainty that she found it [the True Cross]. The old sneer, that there was enough “wood of the cross” to build a ship, though still repeated, has long been nullified. All the splinters and shavings venerated everywhere have been patiently measured and found to comprise a volume far short of a cross. We know that most of these fragments have a plain pedigree back to the early fourth century. But there is no guarantee which would satisfy an antiquary of the authenticity of Helena’s discovery….Even so her enterprise was something life bringing.

She was asserting in sensational form a dogma that was in danger of neglect. Power was shifting. In the academies of the Eastern and South-Eastern Mediterranean sharp, sly minds were everywhere looking for phrases and analogies to reconcile the new, blunt creed for which men had died, with the ancient speculations which had beguiled their minds, and with the occult rites which had for generations spiced their logic….

Everything about the new religion was capable of interpretation, could be refined and diminished; everything except the unreasonable assertion that God became man and died on the Cross; not a myth nor an allegory; true God, truly incarnate, tortured to death at a particular moment in time, at a particular geographical place, as a matter of plain historical fact. This was the stumbling block in Carthage, Alexandria, Ephesus, and Athens, and at this all the talents of the time went to work, to reduce, hide, and eliminate.

And at that crisis suddenly emerged, God-sent from luxurious retirement in the far north, a lonely, resolute old woman with a single concrete, practical task clear before her; to turn the eyes of the world back to the planks of wood on which their salvation hung….

The Cross is very plain for us today; plainer perhaps than for many centuries.What we can learn from Helena is something about the workings of God; that he wants a different thing from each of us, laborious or easy, conspicuous or quite private, but something which only we can do and for which we were created.