Plant fibres, tree bark, strips of leather and animal sinew were not naturally very strong. To prevent them from snapping, they had to be twisted together. Whether very fine fibres, such as those from nettles, coarse strips of tree bark, or vines from the forest, the process was always the same: The individual strands were twisted together to create sturdy cords or ropes. And these were needed almost everywhere – for building houses, tethering animals, as bowstrings, or as a smart belt to fasten trouser legs.