Saint Barbara (d. c. 306 C.E.) was a Christian saint and martyr who died at Nicomedia in today's Turkey c. 306 C.E. Known in the Eastern Orthodox Church as Great Martyr Barbara, Barbara won particular fame for the horrifying fact that her death sentence by beheading was carried out by her own father, a wealthy pagan who had first isolated her in a tower and then denounced her to the Roman authorities when she became a Christian. Her death was attended by numerous miracles, most impressively her father being struck dead by lightning after killing her.
Veneration of Saint Barbara was common from the ninth century until modern times, and she was often depicted in important works of art. She was invoked against the danger of lightning strikes and to insure that a Christian would receive the Eucharist before dying.
Source: New World Encyclopedia