The Book of the Dead was the oldest of the sacred books of Egypt. It was also in universal use. Whatever other articles of belief he may have held, the Egyptian of the historical age was before all things else a follower of Osiris. It was as an Osirian that he hoped to traverse the regions that lay beyond the tomb, and whose geography and inhabitants were revealed to him in the Osirian ritual. From this point of view, accordingly, the Book of the Dead may be termed the Bible of the Egyptians. But it was not without rivals. We have seen that even in the Book of the Dead the heaven of Osiris is not the only heaven to which the dead may look forward. Osiris has a rival in the sun-god, and a place in the solar bark seems almost as much coveted as a place in the fields of Alu. The solar cult of Heliopolis had indeed to yield to the more popular cult of Osiris, but it was on condition that the cult of Osiris recognised and admitted it. To be a follower of Osiris did not prevent the believing Egyptian from being also a follower of the god Ra. In the latter part of the Theban period the solar cult received a fresh impulse and developed a new life. The attempt of Khu-n-Aten to establish a new faith, the outward symbol of which was the solar disc, was but an indication of the general trend of religious thought, and the Asiatic conquests of the Eighteenth Dynasty introduced into Egypt the worship and creed of the sun-god Baal. One by one the gods were identified with Ra; Amon himself became Amon-Ra, and the local deity of Thebes passed into a pantheistic sun-god. It was under these conditions that a new ritual was compiled for the educated classes of Egypt, or at all events was adopted by the religion of the State. This was the Book _Am Duat_, the Book of the Other World. Copies of it are written on the walls of the dark chambers in the rock-cut labyrinths wherein the kings of the Nineteenth and Twentieth Dynasties were laid to rest. In the tomb of Seti I. we find two versions, one in which the text is given in full, another in which the usual plan is followed of giving only the last five sections completely, while extracts alone are taken from the first seven. The text is profusely illustrated by pictures, in order that the dead might have no difficulty in understanding the words of the ritual, or in recognising the friends and enemies he would meet in the other world.