On 27th February in 1900 at the Congregational Memorial Hall on Farringdon Street, not far from St Paul's Cathedral, the Labour Representation Committee was created.
It soon took on a catchier, and more familiar, name:
Facing up to 20th century poverty
Today I'm writing about the creation of the Party, and there'll be a second post to follow on the subsequent century.
It might seem a bit lob-sided. Just one year covered today then 117 years in the next post.
But the foundation of the Labour Representation Committee was about more than just 1900. It was the culmination of a century of British politics and society before that.
These were 100 years of British politics without a working-class, socialist voice in Parliament.
Outside of the Palace of Westminster, things were pretty grim for the majority of people. In Oliver Twist (1838), Charles Dickens wrote that "all poor people have the alternative of being starved by a gradual process in the workhouse, or by a quick one out of it."
By the late-1800s, some people were starting to link these two facts. They saw the Conservative-Liberal monopoly on British politics as the cause of the impoverishment of the working class in British society.
If the social life of Britain was going to change radically, then the workers would need more political power than trade unions and a minority of sympathisers on the Liberal benches.
The solution, it was resolved, was a political party specifically for, of, and about the working class – a Labour Party.
Building a labour party: the man behind the movment
James Keir Hardie was the man who gave more than anyone to making a British Labour Party a reality.
He said in 1898: "To move parliament we must have agitation. There is no other way of creating that public opinion of which we are told that parliament is the vehicle of expression. I admit freely that agitation conducted from the floor of the House of Commons is the most effective, and from this it follows we ought to aim at getting men in."
Hardie, a working-class Scotsman, had gone down the Lanarkshire mines as a child to bring money in for his struggling family. He knew first-hand the cost of Parliament being dominated by the rich. He knew why the workers needed their own political organisation.
But this knowledge didn't make the job of creating such an organisation any easier.
The late-19th century working-class in Britain didn't think with one mind. There was no consensus on what its political and economic objectives should be, nor on how they should be achieved.
There were reformists and revolutionaries. Christian socialists and atheist Marxists. Internationalists, pacifists, and those who had no problem with the British Empire.
Where at one extreme stood the 'Social Democratic Federation', advocating armed revolution against a rigged system, at the other were many major trade union leaders who thought the full interests of labourers could be achieved through an alliance with the Liberals.
Keir Hardie's long battle for a workers party
He kept advocating for an independent political party of the working class until - with revolution as far-off as ever but the workers' problems still left unsolved by successive Liberal prime ministers - 129 Marxists, socialists, intellectuals, and trade unionists gathered in central London on a frosty February morning in 1900.
The room became hushed. The ageing Hardie rose, and spoke:
"I propose the establishment of a distinct Labour group in Parliament, who shall have their own whips, and agree upon their policy."
The simple motion passed.
A new party was born, and Britain would never be the same.
Within just 25 years, Labour had formed a government. Within 50 years, it had formed a majority government.
Today, it has the largest membership of any political party in Europe and is so close to walking into Downing Street again.
Part 2 to follow!