Egyptian mummies were commonly buried with a collection of spells called The Book of the Dead. These spells were designed to provide protection and help the deceased person's spirit navigate through the underworld and into the afterlife. There is no single definitive version of the Book of Dead; the text has many regional variations and changes made by the individual priests who wrote different copies.
The earliest versions of The Book of the Dead date back to Egypt's Old Kingdom, around 2400 BC, and the spells were used consistently through about 50 BC when the practice finally died out. Between 100 and 200 spells were generally contained in the book, and these spells may be loosely divided into four sections. The first section deals with the descent in to the underworld, the second with the restoration of the dead to life, the third with journey the deceased undertakes to meet Osiris and the fourth with the spirit's ultimate judgment.
The spells were usually written on an objects such as a tablet or sarcophagus instead of on papyrus, which has contributed to a relatively large number of surviving copies. They are invaluable in providing an understanding of Egyptian mythology as well as an understanding of the changes the society went through over a period of 2400 years.