A great article on the Levellers

English Civil War Movement that would have implications later...
source: http://www.british-civil-wars.co.uk/glossary/levellers.htm

L evellers were political radicals associated with John Lilburne, Richard Overton and William Walwyn. They had no special name for themselves; the term "Levellers" was coined by their enemies — who included Oliver Cromwell — to imply that they favoured the abolition of property rights and the equalisation of wealth, which they strenuously denied. The Leveller program included religious toleration, reform of the law, free trade, an extended franchise, rights guaranteed under a written constitution and a government answerable to the People rather than to King or Parliament.
Many Leveller ideas were far in advance of their time; their legacy has been claimed as an influence by both socialists and libertarians. It was undoubtedly the first organised activist political movement to emerge in Britain. By 1648, Levellers were organised down to ward and parish level in London, with regular meetings of supporters and organisers in each ward, including women activists. An elected executive committee of twelve members met three times a week to discuss policy and strategy at the Whalebone Tavern, their London headquarters. Subscriptions were collected from members and regulated by two treasurers. The Levellers made full use of the printing press to circulate pamphlets and petitions, effectively developing the first mass political propaganda techniques to be used in Britain. A weekly newspaper, The Moderate, ran from July 1648 until its suppression in October 1649, co-ordinating Leveller supporters across the country.
The movement first emerged amongst middle-ranking civilians in London and southern England as the First Civil War came to an end. In protest at Lilburne's imprisonment by Parliament, Walwyn published England's Lamentable Slaverie in October 1645, in which he stated that Parliament's authority derived from the people who elected it and that Parliament should be answerable directly to them. This was restated in A Remonstrance of Many Thousand Citizens, published by Overton and Walwyn in July 1646, along with calls for the dissolution of the present House of Commons, the abolition of the House of Lords, religious toleration, equality before the law and an ending of trade monopolies. The Remonstrance also expounded the theory of the "Norman yoke", which maintained that the English had enjoyed full constitutional rights and liberties until the Norman conquest, and that William the Conqueror and his successors were tyrannical usurpers. This theory remained central to radical English politics into the 18th century.
Leveller ideas took hold in the New Model Army in 1647 when Agitators were appointed to lobby Parliament for arrears of pay and to protest at Parliament's plans for disbanding part of the Army and committing the rest to an invasion of Ireland. In June 1647, the military Levellers adopted A Solemn Engagement of the Army and succeeded in setting up an Army Council where representatives of the common soldiers sat alongside the senior officers, or "Grandees". The Leveller-influenced manifesto The Case of the Armie Truly Stated called for a new constitution, in contrast to the Grandee Henry Ireton's Heads of the Proposals which outlined a basis for a constitutional monarchy. The military Levellers supported the civilian Agreement of the People, leading to the Putney Debates of October-November 1647 between the Levellers and the Grandees.
Despite a minor military mutiny at Corkbush Field in support of the Agreement, Fairfax and Cromwell kept control of the Army during the Second Civil War and throughout the trial and execution of the King. With the establishment of the Commonwealth, however, the Levellers soon came into conflict with the Council of State. Lilburne, Overton, Walwyn and others were imprisoned in March 1649 for publishing England's New Chains Discovered which criticised the new government for seizing power from the people.
Unrest amongst the Levellers in the Army, fanned by opposition to the Council of State's plans for the invasion of Ireland, led to the Leveller mutinies of April and May 1649. These were quickly and efficiently suppressed by Fairfax and Cromwell. Without the support of the Army, Leveller influence faded very quickly. It had ceased to exist as an organised movement by the end of 1649.
After the establishment of Cromwell's Protectorate in December 1653, some of the most radical of the former Levellers and Agitators became involved in conspiracies to overthrow the Cromwellian régime, which they regarded as a betrayal of the principles for which the civil wars had been fought. John Wildman was arrested in 1655 after conspiring with Royalists, and the Leveller sympathiser Vice-Admiral Lawson was obliged to resign his commission in 1656. The ex-Agitator Edward Sexby plotted to assassinate Cromwell, and attempted to negotiate with Spain to overthrow the Protectorate.