This Greek name for "light" belonged to the Roman empress St. Helena, who was the
mother of Constantine the Great, the 4th-century Roman emperor. Helena was instrumental in discovering important Christian relics, and as tradition states, she found the true cross of Christ during a pilgrimage. She was a wonderful influence on her son and played a crucial role in the Church's history. (You might also like the alternative Eleanor, which can be shortened to Ellie or Nellie.)