YOU might well be tempted to set up The National Anti-Sweating League after getting stuck in a tunnel on the rush-hour Northern Line, but a century ago “sweating” had a particular meaning.

In 1899, the House of Lords committee on sweating (look, I’m sorry, but if you're going to giggle every time, we'll be here forever) defined sweatshop labour by three criteria: it was underpaid, the hours were excessive, and the working conditions were unhealthy.

The point being that they meant bad pay, long days and crap conditions that were dramatically worse than the already dreadful norm.

Many industries at the turn of the century depended on sweating, and vast numbers of women, men and children were its victims.

Trade union activity had begun, to some extent, to improve factory life, but many of the hyper-exploited were homeworkers — getting paid a tiny sum per “piece,” to, for instance, assemble matchboxes in their own homes which they then sold to the match company via an intermediary.

People (especially mothers, or the very elderly) would often work all day and much of the night, to make what even at the time was not considered a living wage.

One of the biggest industries which depended on contracted-out labour was chainmaking.

Heavy chains were made in factories, but there was also an insatiable need, particularly in agriculture, for lighter chains — and the people making them were women in sheds behind their homes, mostly in the English Midlands.

It was piecework, of course, but if you spent 12 hours a day hammering links you might make enough money to supplement your husband’s wage sufficiently to keep the family going.

Are the bosses going to get away with this forever? Don’t worry: they’re not. Here comes Mary Macarthur.

Although she was only 40 when she died in 1921, Macarthur had long since established her place as one of the most consequential trade unionists in the history of the movement.

The middle-class daughter of a Glaswegian draper, Mary moved to London in the early 1900s and became involved in the campaign to win the vote for women.

She fell out with the suffragette leadership, which prioritised getting the franchise for middle-class women rather than for working-class women and men.

Her main area of activity was organising women workers who were not covered by existing trades unions, and especially those employed in sweated industries.

In 1906 Macarthur was one of the founders of the National Anti-Sweating League, following a “sweated industries exhibition” in London.

This imaginative propaganda effort exposed the commodities which were the result of sweating, as well as the conditions under which they were produced. It was enormously popular, visited by tens of thousands; designed to shock, it certainly achieved that aim.

Forced to act, the new Liberal government brought in legislation which set a minimum wage for sweated workers.

But the law contained a loophole the size of the Blackwall Tunnel, as Macarthur discovered when, in 1910, she negotiated a pay structure for the chainmakers of Cradley Heath, whose conditions she described as resembling a “torture chamber of the Middle Ages.”

The employers were legally entitled to delay the pay rises by several months. During this period the chain companies planned to stockpile chains made under the old pay, so that by the time the new rates came into effect there would be a glut in the trade.

The chainmakers would then be unemployed, which would prove to the world that state intervention to raise wages only resulted in workers becoming more destitute than ever.

It didn’t work.

On August 21 1910, the National Federation of Women Workers, of which Macarthur was a leading member, held a meeting at which the chainmakers of Cradley Heath voted to strike in pursuit of an immediate, not a delayed, minimum wage. It was a seminal moment in modern trade unionism.

Just as unions today take to social media platforms to get their message across, so the NFWW used the latest communications technology to mobilise public opinion against the employers.

Macarthur and her comrades ran an unprecedented press campaign, much of which focused on Patience Round, at 79 the oldest of the strikers, having worked at the trade for 67 years.

“These are wonderful times,” Patience told a reporter. “I never thought that I should live to assert the rights of us women. It has been the week of my life — three meetings, and such beautiful talking.”

But the union’s greatest media triumph was persuading Pathe News — which had only launched that same year — to include the strike in its newsreels that were shown in cinemas everywhere and seen by millions.

The employers didn’t stand a chance, as the whole country turned its fury on their trickery and greed.

A solidarity fund set up for the women, to keep them solvent while they weren't working, attracted such support, from all over Britain and around the world, that enough was left over after the strike to build the Cradley Heath Workers’ Institute, a beautiful arts-and-crafts building used as a local union HQ and community centre. (It still exists, now relocated to the Black Country Living Museum.)

It took 10 weeks for the last of the chain companies to surrender, but eventually they all fell into line and something extraordinary had happened: a group of impoverished, previously unorganised female workers had succeeded in enforcing Britain’s first minimum legal wage.

You can sign up for Mat Coward’s Rebel Britannia Substack at rebelbrit.substack.com for more strange strikes, peculiar protests, bizarre boycotts, unusual uprisings and different demos.

The Chainmakers’ Festival 2024 takes place on Sunday September 15 at Mary Macarthur Gardens, Cradley Heath from 11am. More details at www.womenchainmakers.org.uk/events/