From 3500 BC
The cornrow, a hairstyle in which small sections of hair are braided close to the scalp in rows, may be the oldest braiding style. In the 1950s, a French ethnologist and his team found a Stone Age rock painting in the Tassili Plateau of the Sahara. Dating back to 3500 BCE, it showed a woman with cornrows feeding her child from 3500 BCE. And, in a Nigerian clay sculpture from 500 BCE, a figure from the Nok civilization has cornrows etched onto its head.
Depending on the region and group from which it came, the style of the cornrow, from simple linear cornrows to complex geometric ones, helped to express the identity of its wearer: kinship, status, age, religion, and ethnicity. That's a lot to weave into one hairstyle.