The terminology and broad divisions of prehistory are very much Eurocentric because, in the early days, most research was either done in Europe or by Europeans. However, as more and more evidence accumulates from other parts of the world, it has become abundantly clear that these seldom fit the local situation. Nevertheless, they are still widely used in broad terms so it is important to understand them.

At the beginning of the nineteenth century one of the principal aims science was classification. The Swedish botanist, Carl Linnaeus, had led the way with his study of plants and it was another Scandinavian scientist, Christian Jürgensen Thomsen, curator at the National Museum of Denmark in Copenhagen, who was the first to try to bring some order to the physical remains of the human past. He based his system on the technology employed to manufacture the particular artefact, be it a tool or a weapon. He reasoned that stone was unlikely to have been the medium of choice if bronze technology was available and that the same applied with iron over bronze so he categorized objects as belonging to (from oldest to latest) the Stone Age, the Bronze Age and the Iron Age.

Of the three, the Stone Age was by far the longest, accounting for about 98% of the time our species has existed on the planet, a period of at least 2.5 million years (compared to the five thousand years or so that metal has beenused). It was only in the middle of the 19th century that some inkling of this vast scale was generally recognized, along with a recognition of the need to bring more order to it. It seemed logical to suppose that the more carefully finished examples, which were often characterized by fine grinding and polishing (right), were later than the cruder looking chipped material, such as the hand axe shown (above). In 1865, John Lubbock coined the terms Palaeolithic (“old stone age”) and Neolithic (“new stone age”). It soon became apparent that the Neolithic was also characterized by agriculture rather than the hunter/gatherer lifestyle of the Palaeolithic and that it was very much shorter. The switch from foraging to farming occurred at different times in different places but appears to have happened first about ten thousand years ago in the Middle East. It did not begin in Europe until somewhat later and intervening period came to be known as the Mesolithic.

It is the physical remains of various species of Homo together with an interpretation of their behaviour based on the evidence of stone tools and organic remains (animal bones and plant material) that form the basis of our study.Most of the material collected in the early days of the discipline was found in the river systems flowing into the English Channel (La Manche) and the North Sea, especially the Seine and its tributaries. These were alluvial valleys, their gravels and clays eroded upstream and laid down by the river to form terraces. Although it was not possible at the time to date artefacts absolutely, it was clear from what was known of geological processes that the lower levels must be the earliest, and that an enormous amount of time was involved. So, on the basis of their stratigraphic location, a distinction could be made between Lower, Middle and Upper Palaeolithic artefacts. Archaeologists are born cataloguers, however, and subdivisions soon appeared.

These are known as archaeological cultures and are defined as recurring assemblages of artefacts and architectural features (if any) associated with a specific time and place. For example, left is an assemblage from a Beaker Culture burial in Scotland— a typical drinking vessel along with an archer's wrist-guard and a set of arrowheads. In theory, there is no limit to how long or short the period of time might be nor how widespread is the distribution of artefacts. In the early periods, some of them had an almost global reach; in later times they may have been strictly local. They are usually named after the site where the particular assemblage was first discovered (known as the ‘type site’), the geographical region where it predominates, or the artefact (‘diagnostic’) most commonly identified with it. O18