Before hand-knitting was a luxury, it was a lifeline.

On the Western Front, the enemy wasn't only across no man's land. It was the water.

Soldiers stood for weeks in flooded trenches, boots never dry, feet never warm. By the winter of 1914, more than 20,000 British troops had been pulled from the line, not by bullets, but by their own feet. Over the course of the war, trench foot caused roughly 75,000 British casualties. In the worst cases, amputation was the only remedy.

The cause was almost embarrassingly simple: cold, damp, and nothing dry to change into. By late 1915, men were ordered to carry several pairs of clean socks and change them twice a day. Factories couldn't keep pace, so in 1917 the American Red Cross issued an urgent public call for 1.5 million pairs, under a slogan stitched onto posters nationwide: Our Boys Need Sox. Knit Your Bit.

Grandmothers knitted. Schoolchildren knitted. By the war's end, volunteers had produced roughly 23 million garments between them.

A wartime sock had no pattern, no colourway, no name. It existed for one reason, to keep a stranger's feet dry long enough for him to come home. Buried in that plainness was the same idea that still sits underneath good hosiery: something this easy to overlook can be the difference between comfort and real harm.

The sock has always been the quietest garment a person owns.

It has also, at least once, been one of the most important.