When were illuminated letters first used?

Related questions

1. How many types of journal entries are there?
2. What is illumination art?
3. What are types of paper?
4. What is the history of illuminated letters?
5. What material is the Book of Kells written on?
6. Which came first Arabic or Hebrew?
7. What's bullet journaling?
8. What is Article paper?
9. Why is the Book of Kells so famous?
10. What is the biblical definition of illumination?

Tags

1. #these
2. #works
3. #called
4. #middle
5. #illuminated
6. #sometimes
7. #written
8. #history
9. #illumination
10. #books
11. #their
12. #because
13. #manuscripts
14. #incorporation
15. #frequent
16. #original
17. #silver