Beards
I listened to a five-episode history of beards on NRK today. (With with typical euro-centrism they call it "history of beards" while it is only the history of beards in the west.)
The author Anders Kvåle Rue obviously has a strong pro-beard view, and another point he wants to get across. Below is a summary.
Beards have, not surprisingly, been the norm throughout western history - with beardless phases as anomalities. In the "cradle of civilization" (eurocentric again), beards signaled which group you belonged to. To have ones beard shaved off, the fate of slaves and prisoners of war, was the ultimate humiliation. The first beard-free phase was among the soldiers of Alexander the Great, as beards were a drawback in close combat. Later, the Roman soldiers shaved for a similar reason.
The next beard-less phase came during the middle ages, where knights needed a clean shaven face to fit inside their helmets, and the Catholic church wanted its monks to shave as sign of humility. Beards became the norm again in the Renaissance, and - with few exceptions - remained the norm until the early 1900s.
During World War One, soldiers were again required to shave, this time to allow the gas masks to fit closely. Gilette, which made a fortune during that time, engaged in a massive attitude changing ad campaign following WW1 to increase their market.
Clean shaven faces have typically been the expression of submission to authority throughout western history. Clean shaven faces were seen on slaves, soldiers, monks, and now (in a slightly one-sided phrasing) - those enslaved to a consumer culture where sales of shaving implements means big profits.