Mummification is a particular preservation process where the skin and flesh are prevented from decaying. Natural mummification can occur if bodies are left in extreme dry, wet or cold conditions. Deliberately preserving the whole body, either for the life after death or so that the dead person remains part of their community, is practised in many different places.

Whilst the ancient Egyptians were mummifying their dead using natron salts to dry the body, people in Bronze Age Britain were using acid peat bogs to preserve bodies through a tanning process. Two bodies found in the Scottish Hebrides in 2001 seem to have been mummified this way about 1,500 years ago. Their bodies were kept by their community, perhaps in a special house for the ancestors, for about 500 years before they were finally buried.