Black Books

Black Books are tomes of esoteric knowledge found on the island of Solstheim. They are Daedric artifacts of Hermaeus Mora, Daedric Prince of Fate and Knowledge. There are seven known Black Books, 3 of which are guarded by Dragon Priests Zahkriisos, Dukaan and Ahzidal.

Background
The Black Books are tomes which grant the reader great powers. They transport the reader's mind into Apocrypha, a plane of Oblivion by the Daedric Prince Hermaeus Mora. He made them as tools to lure mortals into his service. Many mortals that read these books, remain trapped forever in Apocrypha, to endlessly search for that hidden knowledge and power.

The Dragon Priest Miraak came into possession of one of these books and became the servant of Hermaeus Mora. Eventually he learned great powers, among which is how to bend the will of dragons themselves. The Dwemer discovered another of these books in city of Nchardak sometime in First Era. Since the usage of forbidden knowledge was somewhat a specialty of the Dwemer, they started to study the book and reveal its secrets.