Lancashire weavers would have followed him wherever he led - but he led them into a cul-de-sac and deserted them when they needed him most.
Born into a Protestant family in 1796, O'Connor inherited a Cork estate in 1820 but quickly showed his reforming zeal when he joined Ireland's anti-tithe agitators. He was arrested but not prosecuted, and he used the influence of Daniel O'Connell to win the Cork seat in the 1832 General Election.
His platform included universal suffrage and the adoption of the secret ballot - two of the six points of the Charter which was to occupy so much of his later life.
Single-minded to the point of obsession, O'Connor never let friendships stand in the way of his ambition and soon after arriving in London to take up his seat, he betrayed O'Connell by attempting to oust him as leader of the Irish radicals.
Three years later, he fell foul of the property qualifications for MPs and was unseated. After failing to replace the late William Cobbett at Oldham, he began to carry his reform message around the country, his speeches calling for all the main points of a Charter which was still taking shape in the minds of others: Universal suffrage, annual parliaments, secret ballots, equal constituencies and the end of property qualification for MPs.
In November, 1836, O'Connor joined the London Working Men's Association - whose founders were to frame the Charter - and a few months later he moved to Leeds and opened the radical newspaper The Northern Star.
He used the paper to promote his own ideas of Chartism - he believed in a Physical Force movement which would use direct action to achieve Parliamentary reform.
His ideas angered and sometimes frightened other Chartist leaders, who adopted what they termed a Moral Force approach, although no-one really tried to explain how you could win a moral argument with a government who clearly did not know the meaning of the term as applied to the working classes.
O'Connor would have none of it - the Northern Star and his campaigning speeches were full of blood, thunder and bullets. Yet when it came to the crunch, both sides were found wanting. Parliament rejected a massive petition calling for the adoption of the Charter, and the Chartists retaliated by calling for a "Sacred Month" - a general strike which might bring down
Feargus O'Connor ... fire-and-brimstone campaigner who had the working man eating out of his hand. But ultimately, he failed to deliver and died in a lunatic asylum after contracting syphillis.
This was the case with the Plug Plot of August, 1842. This series of strikes throughout the manufacturing districts had rank-and-file Chartists at its core, yet the NCA was taken by surprise and gave the turn-out its backing only belatedly. When it was over, O'Connor was arrested, but escaped gaol on a technicality.
O'Connor's great land plan of 1845 turned into a fiasco. His dream was to raise cash from workers to buy estates, which would be divided up into four-acre plots, with subscribers drawing lots for the right to occupy a plot and a cottage. He persuaded 70,000 people to contribute £100,000 and with the money bought the Heronsgate estate in Gloucestershire. But within five years the company was being wound up and the "lucky" winners evicted from their homes.
The strain of trying to make a success of the plan may have had a major effect on O'Connor's rationality. He blew Chartism's last big chance when, in April 1848, he claimed that nearly six million people had signed the last Chartist petition to Parliament. Government civil servants counted just 1,975,496 signatures, of which many were clearly forgeries, and the movement never lived down the humiliation.
O'Connor's behaviour now became increasingly bizarre, probably as a result of syphilis, and he was committed to a mental asylum in Chiswick after assaulting a number of MPs. He died on August 30th, 1855.