Can you guess how old these socks are? I'm sure you'd estimate them to be at least a few hundred years old. Would you believe they are over 1600 years old? These socks are Egyptian and date from between A.D. 250 and A.D. 420. That is one colour-fast red dye. The split-toe style would have been created to allow for the wearing of sandals over the socks. I can't imagine that putting sandals over these socks would have looked or felt anything but awkward. Our no-socks-with-sandals prejudice was cemented early and with good reason.
However, though these socks might look knitted, they are in fact not knitting samples but examples of nålebinding, or in English "nailbinding" or "single needle knitting". The single needle used for this technique was crafted from wood or bone that was “flat, blunt and between 6-10 cm long, relatively large-eyed at one end or the eye is near the middle.” Some of what were long thought to be the oldest surviving pieces of knitting have since been determined to be nailbinded — the techniques do produce such similar pieces of work that it can be difficult to distinguish one from the other. Nailbinding, however, is the much older craft. It dates from prehistoric times while the oldest-known examples of knitting date from about 1000 A.D. and knitting is believed to have originated circa 800 A.D..
Nailbinding is slower and more labour-intensive than knitting, but easier on the back, shoulders and hands, and turns out a fabric that is, if less stretchy, more dense and durable. It is still practiced in Peru by the women of the Nanti tribe, an indigenous people of the Camisea region of Peru, who use the technique to make bracelets. Nailbinding is also used in Iran to make socks, and in parts of Scandinavia to make very warm hats, gloves, and other items.
If you'd like to give nailbinding a try yourself, there's a illustrated tutorial here, an instructional video here and samples of nailbinding and other resources at Dilettante.