My object in writing this little book is to give a brief survey of the trend of human migrations so far as our imperfect knowledge permits, and I have endeavoured to do this for various periods of human history, even going as far back as the earliest diffusions that can be predicated. It has not been easy to compress into so small a space the account of the various migrations, indeed little more could be done than merely indicate without describing the movements, their causes and effects. Much interesting information has thus had to be whittled down to a bare statement. I have introduced dates when possible, but in many cases these are only approximate, and it sometimes happens, as in Egyptian chronology, that the system of dating of one authority differs widely from that of another. This is the first time, I believe, that this task has been attempted, and consequently many errors may have crept in. The study of human migrations emphasises the fact that ethnology and history can be satisfactorily elucidated only from the geographical standpoint.