The religions of pre-Indo-European Europe are a large and difficult subject; but a sufficiently wide survey turns out to be less complicated than might seem possible. For full perspective, however, account has to be taken both of Western Asia and of Northern Africa as far as the Guinea Coast and Ethiopia. On the other hand, Indo-European peoples have intruded so far, and also have in turn been overlaid so deeply that it is not always easy to recognize Indo-European survivals at all; wide regions have been stripped—by Islam especially—not only of Indo-European but of the earlier cultures as well.

Though everyone now agrees that the unicorn never existed, this unanimity is quite recent. All through the 19th century there were periodic reports of its presence in darkest Africa or on the Asiatic steppes, and hopes that it would turn out to be a reality died hard. But if there never was such a creature why did the men of the Middle Ages believe in it so firmly and depict it so often? As Christians it was incumbent on them to do so, for it was mentioned in the Old Testament and, therefore, must be real. Its presence there was due to the authors of the Septuagint, the Hellenised Jews who, at Alexandria, in the centuries between the city's foundation and the Christian era, translated their sacred books from Hebrew into Greek and on seven occasions used the word μονόκερως (Greek for unicorn).

The French scholar, Marc Bloch, describes two open field systems in France; the one with long narrow strips grouped in furlongs and ploughed by a long wheeled plough la charrue, the other with small rectangular plots ploughed by a short wheel-less plough, l'araire. R. G. Collingwood has taken up Marc Bloch by suggesting that in England, in Romano-British times, the charrue (carnea) was used on the Villa farms, whilst the araire (aratrum) was employed in the small plots of the villagers, the so-called ‘Celtic Fields’. He further suggests that the Celtic Fields were enclosures.