as Nippur and Shirpurla, were situated farther to the south. It
is on the site of these cities that the recent excavations have
been made, such as those of the University of Pennsylvania
expeditions at Nippur,[6] which are giving us glimpses into
remoter recesses of the historical period.

Even if we disregard the more problematical early dates, we are
still concerned with the records of a civilization extending
unbroken throughout a period of about four thousand years; the
actual period is in all probability twice or thrice that.
Naturally enough, the current of history is not an unbroken
stream throughout this long epoch. It appears that at least two
utterly different ethnic elements are involved. A preponderance
of evidence seems to show that the earliest civilized inhabitants
of Mesopotamia were not Semitic, but an alien race, which is now
commonly spoken of as Sumerian. This people, of whom we catch
glimpses chiefly through the records of its successors, appears
to have been subjugated or overthrown by Semitic invaders, who,
coming perhaps from Arabia (their origin is in dispute), took
possession of the region of the Tigris and Euphrates, learned
from the Sumerians many of the useful arts, and, partly perhaps
because of their mixed lineage, were enabled to develop the most
wonderful civilization of antiquity. Could we analyze the details
of this civilization from its earliest to its latest period we
should of course find the same changes which always attend racial
progress and decay. We should then be able, no doubt, to speak of
certain golden epochs and their periods of decline. To a certain
meagre extent we are able to do this now. We know, for example,
that King Khammurabi, who lived about 2200 B.C., was a great
law-giver, the ancient prototype of Justinian; and the epochs of