Christian Saints

St. Helen (also Helena, Elena, Hélène). Helen was the Christian wife of Constantius Chlorus. On becoming Emperor of the Gauls in 292 he repudiated her, but her son Constantine (306-337) became the first Christian Emperor.
St. Helen was very enthusiastic about searching for relics of Christ.  She traveled to Palestine around 327, where she apparently discovered all tree crosses of Golgotha as well as the nails used to crucify Christ. There are varying explanations as to how she was able to differentiate the True Cross from the other two. The Golden Legend states that Helen was informed by a Jew called Judas; other explanations are that there were still the inscription in three languages fixed on it, and besides after its discovery the True Cross performed the numerous miracles.
Helen founded churches in Palestine and throughout the Empire and encouraged the growth of Christianity throughout the Western world.
See: Cima da Conegliano. St. Helena.
Paolo Veronese. St. Helena. Vision of the Cross.

Recommended reading:
The Book of Saints: The Lives of the Saints According to the Liturgical Calendar by George Angelini, Victor Hoagland (Editor). Regina Press, Malhame & Company, 1986.
365 Saints: Your Daily Guide to the Wisdom and Wonder of Their Lives by Woodeene Koenig-Brick (Author). Harper SanFrancisco, 1995.
Helena Augusta: The Mother of Constantine the Great and the Legend of Her Finding of the True Cross by Jan Willem Drijvers. Brill Academic Publishers, 1997.