Her story says that Barbara was a beautiful girl who dwelt in the city of Nicomedia in Asia Minor. Dioscurus, her cruel pagan father, had her shut in a tower in order to preserve her from suitors. She nevertheless secretly converted to Christianity. Her father commanded that she be built a bath-house, so that she would not have to use the public baths. The design for the bath-house originally had two windows, but Barbara had a third installed to commemorate the Trinity. Her father, seeing this change, discovered that she was a Christian. He had her taken to a Roman imperial magistrate during a persecution of Christians, who ordered her to be beheaded, and directed that her father carry out the sentence himself. He did so, but was struck dead by lightning in divine retribution.
Her association with lightning caused her to be invoked against lightning and fire; by association, she also became the patron of artillery and mining. Her feast was formerly celebrated on December 4; in the 1969 reform of the Roman Catholic liturgy it was downgraded to a purely local celebration, and her name was dropped from the litany of saints. She was formerly one of the Fourteen Holy Helpers.
She is depicted in art as standing by a tower with three windows, carrying a palm branch and a chalice; sometimes cannons are depicted by her side. Because of her identification with lightning and cannonry, in Santeria she is identified with the god Ogun, god of lightning and war.