For over 99 per cent of the time that human communities have lived in what is now Britain, hunting and gathering were the mainstays of the subsistence economy. Such a lifestyle involves small, highly mobile, kinship-based groups of men, women, and children with a minimum of equipment and possessions. Archaeologically, such lifestyles leave frustratingly little trace. No structures except basic shelters were erected by hunter-gatherers and they lived within the constraints of their environment rather than by modifying it.