The New Student's Reference Work/Lucifer

Lu′cifer (Latin, “light-bringer”), the name given to Venus as the morning-star. The early fathers of the church attached this name to Satan, in the belief that Isaiah xiv. 12, which refers to the king of Babylon, contained a reference to the prince of darkness. In Milton's Paradise Lost, also, Lucifer is the original name of the archangel (now called Satan), who fell and dragged down to hell the third part of the host of heaven.