Relations of Sumer and Akkad with other lands--Cultural influences, carried by the great trade-routes, often independent of political contact--The prehistoric relationship of Sumerian culture to that of Egypt--Alleged traces of strong cultural influence--The hypothesis of a Semitic invasion of Upper Egypt in the light of more recent excavations--Character of the Neolithic and early dynastic cultures of Egypt, as deduced from a study of the early graves and their contents--Changes which may be traced to improvements in technical skill--Confirmation from a study of the skulls--Native origin of the Egyptian system of writing and absence of Babylonian influence--Misleading character of other cultural comparisons--Problem of the bulbous mace-head and the stone cylindrical seal--Prehistoric migrations of the cylinder--Semitic elements in Egyptian civilization--Syria a link in the historic period between the Euphrates and the Nile--Relations of Elam and Sumer--Evidence of early Semitic influence in Elamite culture and proof of its persistence--Elam prior to the Semitic conquest--The Proto-Elamite script of independent development--Its disappearance paralleled by that of the Hittite hieroglyphs--Character of the earlier strata of the mounds at Susa and presence of Neolithic remains--The prehistoric pottery of Susa and Mussian--Improbability of suggested connections between the cultures of Elam and of predynastic Egypt--More convincing parallels in Asia Minor and Russian Turkestan--Relation of the prehistoric peoples of Elam to the Elamites of history--The Neolithic settlement at Nineveh and the prehistoric cultures of Western Asia--Importance of Syria in the spread of Babylonian culture westward--The extent of early Babylonian influence in Cyprus, Crete, and the area of Aegean civilization APPENDICES I. Recent Explorations in Turkestan in their Relation to the Sumerian Problem II. A Chronological List of the Kings and Rulers of Sumer and Akkad INDEX LIST OF PLATES I. Stele of Narâm-Sin, representing the king and his allies in triumph over their enemies Frontispiece II. Doorway of a building at Tello erected by Gudea; on the left is a later building of the Seleucid Era III. Outer face of a foundation-wall at Tello, built by Ur-Bau IV. Limestone figure of an early Sumerian patesi, or high official V. Fragment of Sumerian sculpture representing scenes of worship VI. The Blau monuments VII. Diorite statue of Gudea, represented as the architect of the temple of Gatumdug