Old English legend made her the daughter and heiress of Old King Cole (Coel); Trier in Germany claimed her as one of a noble family there. It is more likely that she came from humbler surroundings; one biographer referred to her as an innkeeper, but a "good innkeeper".
She married a soldier named Constantius - later a colleague and Caesar ("junior emperor") of the Roman emperor Maximian - and by him became the mother of Constantine. When their son was a teenager, Constantius divorced Helena in order to make a more politically advantageous match with Maximian's step-daughter, Theodora. Helena and Constantine went to live at the court of Diocletian, the superior and co-emperor of Maximian (yes, that same Diocletian mentioned in the accounts of so many martyrs), and little more is known of her until after her son was proclaimed emperor in 306 upon the death of his father and defeated his rival Maxentius at Milvian Bridge in 312 (the famous "In Hoc Signo Vinces" episode).
|Coin of Empress Helena, courtesy of Classical Numismatic Group, Inc.|
She died soon after, possibly on the way home, and was buried in a mausoleum in Rome. The tomb falling into disrepair, her sarcophagus was moved to the Vatican, and can be seen in the Museo Pio-Clementino there (although some accounts say that she was buried in the Church of the Holy Apostles in the eastern Roman capital of Constantinople). The Orthodox Church reveres her and her son as "Equal to the Apostles" for their work in promulgating the Faith, and indeed, it was her work that did so much to revive the interest in - and reverence for - the sacred localities and their associations.
She is the patron of divorced women, converts, and archaeologists (and by extension, perhaps historians? We dig through mounds of paper rather than dirt, but the aim is the same - the discovery of Truth).
Saint Helena, Giovanni Baptista Cima (Cima da Conegliano), 1495, National Gallery of Art, Washington.