1. Leonardo da Vinci's Artwork:
- The book accurately refers to Leonardo da Vinci's artistic work, including "The Last Supper" and "Mona Lisa."
2. Leonardo da Vinci's Secret Knowledge:
- Brown suggests Leonardo da Vinci held hidden knowledge, which is fictional.
3. Opus Dei:
- Opus Dei is a real organization, although its portrayal in the book is highly dramatized.
4. Templars and Holy Grail:
- The Knights Templar were a real historical order, but their connection to the Holy Grail and the modern world is fictional.
5. Sophie Neveu:
- Sophie Neveu is a fictional character.
6. Robert Langdon:
- Robert Langdon is a fictional character.
7. Secret Societies and Conspiracies:
- The idea of secret societies like Sion Priory, the Prieuré de Sion, and their links to Jesus' bloodline is mostly fiction.
8. Religious Controversies:
- The book explores discussions on the Holy Grail, the true identity of Jesus, and alternate versions of the Biblical narrative. These topics are debated in religious scholarship but depicted fictionally in the novel.
Overall, while Dan Brown draws on historical elements, the vast majority of the plot, characters, and conspiracies presented in The Da Vinci Code are fictional.