Medieval times were more known for what the women didn't show than what
they did. Many times the caps and headdresses of women concealed the
hair completely, though often with only a hint of well-groomed hair
peaking from the edges.
The Middle Ages had their troubles, from religious fervor to witchcraft and to disease, such as the Bubonic Plague. Perhaps, there were centuries of fear, founded on a combination of burgeoning science and religious fanaticism. It was a good policy not to upset one's Maker and to appear moderate and pious at all times. Showing hair, therefore was flashy and upsetting.
When the hair did appear it was close to the head and usually braided. The commoners might let it hang loose, but it wasn't good to show your hair in public, or even use a lot of make-up items, as you could be accused of witchcraft. The slightest upset in the world required someone to blame, and it was safer to choose features from the garb of a religious follower than to stand out in a crowd, by flaunting flowing tresses, and risking accusations.
Medieval braiding became the standard for having your hair done. There
was the three-strand braid, the four-strand braid, the twist-and-cross,
and the weaving style. These were the realm of the nobility and the
wives of men of means. Expert hairdressers were required, but after all
was done, most of the artistic features were cowled under caps and head
pieces, almost as if the woman of the middle ages wanted to feel
feminine and attractive, but was too afraid to show it to the outside
world. As a youth, she still had to attract a member of the opposite
sex. But as many well-to-do families were eager to control a daughter's
choice of husband because of its financial benefit to the family,
arranged marriages were common, so the need to display one's feminine
attributes, particularly the hair, was unnecessary.
As usual, the leaders in the court set the trends, so when Elizabeth the First came to power in England, her red hair and white complexion sent the ladies of nobility to seeking white powder and red wigs. The powder they used contain white lead, a dangerous poison. The women were equally intent upon plucking out their eyebrows completely, creating a look that has never again been equalled.