118th Pope of the Catholic Church. Pontificate 903 - 903. Leo was Pope for some thirty days in 903 after the death of Pope Benedict IV (900–903). He was dethroned by antipope Christopher (903–904), who is sometimes considered a legitimate pope. Elected while a priest, Leo V's pontificate occurred in the darkest period of papal history. He was deposed and murdered, presumably strangled by Christopher, who was in turn executed by Pope Sergius III (904–911) in 904.