However, in this phase of Egyptian civilization, signs of contact with a yet more distant region are also found. They differ in character from those we have just mentioned. Libya, Sinai, and Syria supplied the Nile valley with much-needed raw materials; but Sumer supplied ideas. Imported Mesopotamian cylinder seals have been found in Egypt, and the same odd form of seal was adopted in Egypt. The earliest Egyptian brick buildings resemble the Protoliterate temples of Mesopotamia in all significant matters of technique. Egyptian art—even in the Narmer palette—used Mesopotamian motifs. Even writing seems to have been due to the stimulus derived from acquaintance with Mesopotamian writing of the end of the Protoliterate period. We have dealt with these matters in an Appendix. For although it is certain that contact between the two great centres of the Near East took place, it did not affect the social and political sphere with which we are concerned here. In fact, if we look back over the evidence presented in this chapter, the autochthonous character of the Egyptian development is unmistakable. The basic structure of the society which emerged was the direct opposite of that which came into being in Mesopotamia. In Egypt the great change did not lead to a concentration of social activity in urban centres. It is true that there were cities in Egypt, but, with the single exception of the capital, these were no more than market towns for the countryside. Paradoxically enough, the capital was less permanent than the towns in the provinces, for in principle it served for only a single reign. Each pharaoh took up residence near the site chosen for his tomb, where, during the best part of his lifetime, the work on the pyramid and its temple continued, while the government functioned in the neighbouring city. But after his death the place was abandoned to the priests and officials who maintained his cult and managed his mortuary estate, unless the new king decided to continue in residence because the adjoining desert offered a suitable site for his own tomb. Until the middle of the second millennium B.C. (when Thebes assumed a metropolitan character) there was no truly permanent capital in Egypt, a situation which clearly demonstrates the insignificant role played by the concept of the city in the political thought of the Egyptians.[143] In Mesopotamia, on the other hand, even the most powerful rulers of the land styled themselves rulers of cities and functioned as such, in Akkad or Ur, in Babylon or in Assur.