So people had to pass the tests. But what else must they do to live forever? Gradually it came to be believed that the body must be preserved, too, and from this belief, and an accident of the desert climate, came mummification.

When people are buried in the dry salty sands of the desert, their bodies do not rot away, but instead dry out. This is a kind of natural mummification. But when the ancient Egyptians began burying their dead in coffins to protect them from wild animals the bodies began to decay. So the ancient Egyptians had to find a way of copying nature.

The earliest surviving Egyptian mummies date from around 3200 BC.