History in its broadest sense should be a record of Man and his accomplishments from the time when he ceased being merely an animal and became a human being. The efforts to reconstruct this record may be classed under two heads: (1) History (in the stricter sense), which is based on written documents and covers part of the last five thousand years of Man’s activities, and (2) Prehistory, which is based largely on archaeological evidence and covers all the long preceding period, which probably amounts to more than one million years.
The prehistoric period is important, not only by reason of its vast length, but also because during this time Man made almost all his major discoveries and adaptations to environment and group-life (except those connected with the recent machine age) and evolved physically into the modern racial types. Hence at least a brief summary of the prehistoric period is a necessary introduction to any account of the recorded history of Man.
The main body of material upon which the work of prehistoric reconstruction is
based comprises: first, remains left by early peoples, largely in the form of tools and other artifacts, found by excavation in old habitation sites or burials; secondly, other traces of their activities, such as buildings and rock-carvings or rock-paintings; and lastly, the bones of the people themselves. This material gives good evidence of the physical type of prehistoric peoples and their material culture, very slight evidence of their social, intellectual, and religious life and no evidence of their language. It can be supplemented to some extent-and with great caution-by a comparative study of the physical types, languages, and material culture of modern peoples.
The time when prehistory ends and true history begins varies greatly in different parts of the world. Traditional history often covers the borderline between the two and can sometimes be successfully correlated with the archaeological evidence.
In prehistory, dates are entirely a matter of estimate and cannot be used as fundamental landmarks, as in the case of recorded history.