She was born in the lower classes[2] traditionally in the city of Drepanon, Bithynia, in Asia Minor, which was renamed Helenopolis in her honor, although several locations have been proposed for her birthplace and origin.

In her final years, she made a religious tour of Syria Palaestina and Jerusalem, during which ancient tradition claims that she discovered the True Cross.

Though Helena's birthplace is not known with certainty,[3] Helenopolis, then Drepanon, in Bithynia, following Procopius, is the one supported by most secondary sources,[4] and by far the most likely candidate for her place of origin.

[13][6] The historian Cyril Mango has argued that Helenopolis was refounded to strengthen the communication network around Constantine's new capital in Constantinople, and was renamed simply to honor Helena, not to necessarily mark her birthplace.

He makes this comment a virtue, calling Helena a bona stabularia, a "good stable-maid",[20] probably to contrast her with the general suggestion of sexual laxness considered typical of that group.

[18] Some ancient historians, "pagan and therefore hostile to the family ... suggested that as a girl she had been one of the supplementary amenities of her father's establishment, regularly available to his clients at a small extra charge.

"[22] Both Geoffrey of Monmouth and Henry of Huntingdon promoted a popular tradition that Helena was a British princess and the daughter of "Old King Cole" from the area of Colchester.

[24] The historian Timothy Barnes has suggested that Constantius, while serving under Emperor Aurelian, could have met her while stationed in Asia Minor for the campaign against Zenobia.

[citation needed] Barnes calls attention to an epitaph at Nicomedia of one of Aurelian's protectors, which could indicate the emperor's presence in the Bithynian region soon after AD 270.

[27] Some scholars, such as the historian Jan Drijvers, assert that Constantius and Helena were joined in a common-law marriage, a cohabitation recognized in fact but not in law.

[32] In order to obtain a wife more consonant with his rising status, Constantius divorced Helena some time before 289, when he married Theodora, Maximian's daughter under his command.

[33] The narrative sources date the marriage to 293, when Constantius was appointed caesar (heir-apparent) of Maximian, but the Latin panegyric of 289 refers to the new couple as already married.

Constantine was proclaimed augustus (emperor) in 306 by Constantius' troops after the latter had died, and following his elevation his mother was brought back to the public life in 312, returning to the imperial court.

[39] Local founding legend attributes to Helena's orders the construction of a church in Egypt to identify the Burning Bush of Sinai.

[36] Emperor Hadrian had built during the 130s a temple to Venus over the supposed site of Jesus' tomb near Calvary, and renamed the city Aelia Capitolina.

[42] According to tradition, Helena ordered the temple torn down and, according to the legend that arose at the end of the 4th century, chose a site to begin excavating, which led to the recovery of three different crosses.

The legend is recounted in Ambrose, On the Death of Theodosius (died 395) and at length in Rufinus' chapters appended to his translation into Latin of Eusebius's Ecclesiastical History, the main body of which does not mention the event.

I have no greater care than how I may best adorn with a splendid structure that sacred spot, which, under Divine direction, I have disencumbered as it were of the heavy weight of foul idol worship [the Roman temple]; a spot which has been accounted holy from the beginning in God's judgment, but which now appears holier still, since it has brought to light a clear assurance of our Saviour's passion.

Local tradition holds that she imported hundreds of cats from Egypt or Palestine in the fourth century to rid a monastery of snakes.

Later legends depict her as bringing with her large parts of the True Cross and other relics, which were then stored in her palace's private chapel, now the Basilica of Santa Croce in Gerusalemme, where they can be still seen today.

[45] Some of her remains were subsequently moved to the Relic Crypt of St. Helena at Église Saint-Leu-Saint-Gilles in Paris, where they are under the supervision of local Russian Orthodox priests.

After adding frankincense to it, the bonfire was lit and the smoke rose high up to the sky and returned to the ground, exactly to the spot where the Cross had been buried.

[54] Portions of her relics are found at the basilica of Santa Maria in Ara Coeli in Rome, the Église Saint-Leu-Saint-Gilles in Paris, and at the Abbaye Saint-Pierre d'Hautvillers.

In 1517, the English priest, Richard Torkington, having seen the relics during a visit to Venice described them as follows: "She lith in a ffayr place of religion, of white monks, ye may see her face perfythly, her body ys covered with a cloth of whith sylke ... Also there lyes upon her breast a lytell crosse made of the holy crosse ..."[55] In an ecumenical gesture, these relics visited the Orthodox Church of Greece and were displayed in the church of Agia Varvara (Saint Barbara) in Athens from 14 May to 15 June 2017.

The statement made by English chroniclers of the Middle Ages, according to which Helena was supposed to have been the daughter of a British prince, is entirely without historical foundation.

St Helen's Chapel in Colchester was believed to have been founded by Helena herself, and since the 15th century, the town's coat of arms has shown a representation of the True Cross and three crowned nails in her honour.