However, Lucifer is only mentioned once in the Bible, in the Isaiah 14:12. However, only in translations based on the Latin translation largely made by St. Jerome in the fourth century. The hebraic texts is not about a fallen angel, and the hebraic texts sais "Day star, son of Dawn" - which is a metaphor for a fallen Babylonian king, which had mistreated the children of Israel. One can only guess that St. Jerome mistook "Day star, son of Dawn" to mean the planet Venus, which then went by the name of Lucifer.
The misunderstanding developed during centuries, and Lucifer came to be Satan, the Devil, and even the [Prince of Darkness]? in christian tradition.