3. Mesolithic

Around 10,000 years ago the ice age finally ended. Temperatures rose, probably to levels similar to those today, and forests expanded further. By 8,500 years ago, the rising sea levels caused by the melting glaciers cut Britain off from continental Europe for the last time. The warmer climate changed the arctic environment to one of pine, birch and alder forest; this less open landscape was less conducive to the large herds of Reindeer and Wild Horse that had previously sustained humans. Those animals were replaced in people's diets by less social animals such as elk, red deer, roe deer, wild boar, and aurochs, which would have required different hunting techniques in order to be effectively exploited.

Tools changed to incorporate barbs which could snag the flesh of a hunted animal, making it harder for it to escape alive. Tiny microliths, blades of three santimetres or even less, were developed for hafting onto harpoons and spears. The dog was domesticated because of its benefits during hunting and the wetland environments created by the warmer weather would have been a rich source of fish and game. It is likely that these environmental changes were accompanied by social changes with the groups that inhabited Britain at this time. Humans spread and reached the far north of Scotland during this period.

People of the period were actively managing their environment by deliberately setting fire to the reeds immediately in front of the encampment. They also demonstrated unexpectedly sophisticated carpentry skills. Excavations at Howick in Northumberland uncovered evidence of a large circular building dating to c. 7,600 BC which is interpreted as dwelling. Now there is a reconstruction of that house, based on post-holes. The substantial size of the timbers used suggests that the roof was covered with bark or turf, rather than skins. The house was first built c.7,800 BC, and indicates it was in use for at least 100 years, though whether this was on a permanent or seasonal basis is not clear.

The view of Mesolithic Britons as being exclusively nomadic is now being replaced with a more complex picture of seasonal occupation or in some cases, permanent occupation and attendant land and foodsource management where conditions permitted it.

4. Mesolithic-Neolithic Transition

It is likely that the bounteous nature of the Mesolithic environment and ancient Britons' success in exploiting it eventually led to exhaustion of many natural resources. The remains of a mesolithic elk found caught in a bog at Poulton-le-Fylde in Lancashire demonstrated that it had been wounded by hunters and escaped on three different occasions, indicating over-hunting during the Mesolithic. A few Neolithic monuments overlie Mesolithic sites but little direct continuity can be demonstrated. Farming of both crops and domestic animals was adopted in Britain around 4,500 BC at least partly because of the need for reliable food sources. Hunter-gathering ways of life would have persisted into the Neolithic at first but the increasing sophistication of material culture with the concomitant control of local resources by individual groups would have caused it to be replaced by distinct territories occupied by different groups.