Early Humans were running around barefoot, then at some point we had some kinds of basic shoes (sandal things?), and then later shoes/boots that covered the foot.
Somewhere in here, someone had the bright idea to sheathe their foot in something (modern day cloth/socks) in order to prevent all that rubbing/chafing of ankles and the wide bits just behind the toes, and we're forever thankful (wear shoes for a day without socks and find out real quick...)
...but where did this practice start? Did it start with cloth or did people use things like mud or the like? And how did it manage to catch on, and then to spread all over the world so prevalently as it has today?
(Was just a random question I stumbled onto throwing on my shoes sans socks to run outside for something real quick, and I started wondering where the idea of socks DID come from and how it's so universal today in much of the world...)
A small addendum to your premise and slight answer to the 'where did this practice start– mud?', there was an intermediary to prevent chafing, add insulation, help wick away moisture and generally fill in the shoe– moss and dry grass. This is going into archaeology, but Ötzi 'the Iceman' was a 5000+ year-old mummy who was found in the Alps with excellently preserved clothing. This image is a modern reconstruction of the layers of his shoes– the innermost layer was a net of bark filled with dry grass, with moss for padding. Then the rest of the shoes were a variety of animal leathers and skins stitched together. The idea of a soft and dry replaceable interior was there, long before the sock.
