Why do barbershops have a red, white and blue spinning pole?

You are standing outside a barbershop, waiting for a haircut, watching that red, white and blue pole spin round and round. It looks like a toy. It is actually one of the oldest shop signs in the world — and it is not advertising haircuts.

In the Middle Ages, a barber did much more than hair. He had sharp razors and steady hands, so he also pulled teeth, set broken bones, cut open boils, and sometimes even cut off a limb. People called him a barber-surgeon. Back then, doctors believed sickness came from your "humours" being out of balance, and that letting some blood out would fix it. But doctors thought cutting was beneath them, so the bloodletting was handed to the barber.

That is where the pole came from. The pole itself is the wooden stick the patient squeezed during bloodletting — the tighter you squeezed, the better the blood was said to flow. The brass basin on top held the leeches, the little worms that suck blood. The basin at the bottom caught the blood that ran down. And the red and white stripes? One is blood, the other is the bandage.

The colours later became a menu. In Renaissance Amsterdam, surgeons used the stripes to show what they could do: red meant they would bleed you, white meant they could set bones or pull teeth, and blue meant that if nothing more urgent came up, they would give you a shave.

In 1745 the surgeons in England finally pushed the barbers out of their guild, and the two trades split. But the pole stayed, and it is still spinning.

Try this: next time you pass a barbershop, look up and check whether the two little basins are still there. Many new shops have dropped them. Where they survive, you now know what they used to hold.