Alongside these changes in the burial position progressed the art of preserving the body. The earliest attempts were made on the body of the king; and the knowledge of embalming gained in preserving his body was gradually utilized for the higher classes and finally for all but the poorest. It seems indisputable that the royal personages of the Fourth and Sixth Dynasties were mummified--i.e., the entrails were drawn, the body prepared with spices and resins and wrapped tightly in cloths smeared with resin. But the mummies of the nobles, even of this period, show no trace of such treatment. The receptacles for the viscera are sometimes found in their graves in the Sixth Dynasty, but are, as a rule, empty, being mere dummy vases. Even in the Middle Empire, the preservation of the bodies of the better classes was extremely imperfect. The bundles of wrappings have kept their form to the present day and it seems as if the mummy were still intact; but an examination of the interior shows only loose bones. Successful mummification appears among better-class people in the New Empire for the first time and becomes a general custom in the Late Period. The processes of successful mummification necessitated the practical destruction of the body. In the Middle Empire, which is the period under discussion, the process of mummification had reached a middle stage, and, while we are unable to explain exactly the causal relationship, it is clear that this advance in the treatment of the body accompanied a spread of the belief in the Osirian immortality. VII. THE NEW EMPIRE The New Empire (1600-1200 B.C.) was the great period of foreign conquest. The Hyksos, Asiatic invaders, had held Egypt for a century or more. The Theban princes who drove them out became kings of Egypt, and followed them into Asia. With an army trained in war by the long struggle with the Hyksos, the Egyptian kings, having tasted the sweetness of the spoils of war, entered on the conquest of western Asia and the Sudan. The plunder of both these regions poured into Egypt. Under Thothmes III an annual campaign was conducted into Syria to bring back the spoils and the tribute. Foreign slaves and the products of foreign handicraft were for sale in every market-place. The treasury was filled to overflowing. A large share was assigned to Amon, the god of the Theban family. Temples were built for him; estates established for the maintenance of his rites; thousands of priests enrolled for the service of his properties. The god became, in a material sense, the greatest god of Egypt, the national god; and his priesthood became the most powerful organization in the kingdom. The high priest of Amon usurped the power of the king and finally supplanted him. Such was the period in which the next great development of the Egyptian idea of immortality is to be noted-- a period of priestly activity in the beginning and of priestly domination in the end.