When a group of rural Norfolk children downed books and emblazoned their classroom blackboard with the words: 'We are going on strike tomorrow', little did they know the shock waves it would create.
The protest over the unfair dismissal of two teachers, husband and wife Kitty and Tom Higdon, drew support from across the country and was to carry on for 25 years - still the longest strike in British history.
And tomorrow marks a milestone in the story of the Burston Strike School, now considered a watershed of the labour movement.
The Strike School and its nearby green will host a rally to mark 100 years since the official opening of the building in 1917.
Shaun Jeffery, Strike School historian and one of the organisers of the annual rally, said the strike's importance could not be understated.
Mr Jeffrey, 40, from Beccles, said: 'People from across the country were inspired by what happened at Burston. They could see than an injustice was being done to these teachers and they sent whatever support they could.'
Mr and Mrs Higdon were popular among pupils and their parents, and they worked hard to improve hygiene and comfort at the school and encouraged the children to see learning not as a chore, but as a pleasure.
But they were dismissed in 1914, after they fell into conflict with the school's committee, which was made up of local farm owners who often had different priorities.
The day after the message was left on the blackboard a group of children, led by a pupil called Violet Potter, marched around the village waving signs, playing instruments and demanding their favourite teachers back.
A temporary Strike School was set up in a workshop, with the Higdons continuing to teach the majority of the village's children. After word had spread, donations poured in from trade unions and Labour party branches which funded the building of the Strike School that still stands today. Violet officially opened the building on May 13, 1917.
A council-run school carried on, but many of its pupils were brought in from nearby villages. The Strike School pupils' parents were fined and even threatened with eviction if they did not send their children back to the council school, but they closed ranks and continued to support the Strike School.
MORE: John McDonnell and Len McCluskey to attend rally at Burston Strike SchoolMr Jeffery said the strike illustrated the kind of class struggle that was happening across the country in the early part of the 20th century.
He said: 'Agricultural workers were the most vulnerable workers in society at the time, and the landowners had incredible leverage over their lives.
'If they didn't do what a farmer wanted they could be blacklisted and even evicted from their homes.
'But they stuck to their firm belief that the Higdons were being victimised and were unfairly dismissed from their jobs. And because they remained absolutely resolute, they basically won.
'It's really about solidarity - If you have solidarity you can illicit change and reach a positive outcome but if you stand alone then you have no chance.'
The strike only ended after Mr Higdon died in 1939, and Mrs Higdon, then 75, was unable to carry on alone.
Mr Jeffrey said: 'They had annual rallies back in the 1920s, and they went on until 1937. Even in those days some big names like Keir Hardie and Sylvia Pankhurst came to speak. And 100 years later you are still seeing the biggest names in the labour movement come down and show their support.
MORE: Jeremy Corbyn addresses issues faced by rural residents at Burston Strike School RallyAnnual rallies to commemorate the strike began again in 1983, and they continue to attract visitors from far and wide.
For the past two years, Labour leader Jeremy Corbyn has spoken at the rally, and this year guest speakers will include shadow chancellor John McDonnell and Unite the Union general secretary Len McCluskey.
Mr Jeffrey said the Strike School rally had become one of the labour movement's four major events along with the Women Chainmakers' Festival, the Durham Miners' Gala and the Tolpuddle Martyrs' Festival.
He said he had written a history of the Strike School with the working title The Higdons and the Village in Revolt, which should be published next year. A film about the Strike School, called Burston, is also planned.
The rally will take place tomorrow from 10.45am to 4pm. Visit burstonstrikeschool.co.uk for more information.
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