Saint Barbara was a beautiful young lady possibly of Asia Minor descent (though some stories say she lived in Heliopolis). She apparently lived during the early part of the 4th century (though again some references place her in the early part of the 3rd century). She was the daughter of a wealthy nobleman and merchant, Djoscorus, who was a pagan.

Tradition provides that Djoscorus built a magnificent tower to safeguard his daughter, perhaps from the growing influence of Christianity. However, during his frequent business trips abroad, she was converted to Christianity.

Legend has it that when her father discovered her conversion (possibly when Saint Barbara tried to convert him), in a fit of rage, he turned her over to Marcian, the Roman prefect who, under the watching eyes of her father, was to torture her until she denied Christ. She was stripped and struck with whips and clubs until she stood in a pool of her own blood, yet she would not deny Christ. Afterwards, she was thrown in to prison where, during the night, god completely healed her wounds and filled her with heavenly joy.

The next day, while Marcian was amazed to see her wounds had healed, he demanded that she denounce Christ, and when she refused. After additional torture, Marcian became frustrated with her, and ordered her to be taken out and killed. It was her father himself who led her from the city and with his own sword, decapitated her (along with her servant and friend, Juliana). On his way home, however, a god had him struck by a bolt of lightning, killing him instantly.

The Cairo church that is now dedicated to her in Old (Coptic) Cairo stands north of the Coptic Museum and to the east of the Church of Saints Sergius and Bacchus (Abu Serga), on the eastern side of Fort Babylon. Al-Maqrizi tells us that it was the most famous and beautiful church of his time in Cairo, but exactly when the Church of St. Barbara was built is speculative to some extent.