In 1815 William Cobbett, Major John Cartwright, Sir Francis Burdett and Henry 'Orator' Hunt were the most important figures in the Radical reform movement in Britain. Whereas Cobbett had used his weekly journal, the Political Register, to advocate parliamentary reform, Cartwright, now in his seventies, concentrated on helping the formation of Hampten Clubs. Cartwright's ideas had a large impact on Manchester and by 1817 there were several Hampden Clubs in the area.
However, it was Henry Hunt who had established himself as the most popular of the radical leaders in Lancashire. With the reputation as being the best public speaker in England, Hunt drew large crowds to meetings all over the country. Although from a privileged background, Hunt, was the acknowledged leader of working-class radicals.
Hunt had a large following in Manchester. A group of Hunt's supporters, including James Wroe, John Knight, Joseph Johnson and John Saxton, started the weekly newspaper, the Manchester Observer in 1818. Wroe became the newspaper's first editor and within twelve months the Manchester Observer was selling 4,000 copies a week. Although it started as a local paper, by 1819 it was sold in most of the large towns and cities in Britain. Henry Hunt called the Manchester Observer "the only newspaper in England that I know, fairly and honestly devoted to such reform as would give the people their whole rights."
In March 1819, Joseph Johnson, John Knight and James Wroe formed the Patriotic Union Society. All the leading radicals in Manchester joined the organisation. Johnson was appointed secretary and Wroe became treasurer. The main objective of this new organisation was to obtain parliamentary reform and during the summer of 1819 it decided to invite Major Cartwright, Henry Orator Hunt and Richard Carlile to speak at a public meeting in Manchester. The men were told that this was to be "a meeting of the county of Lancashire, than of Manchester alone. I think by good management the largest assembly may be procured that was ever seen in this country." Cartwright was unable to attend but Hunt and Carlile agreed and the meeting was arranged to take place at St. Peter's Field on 16th August.