The English Civil War started in 1642, when the King tried to take over parliament by force. He was unsuccessful, and Oliver Cromwell built up the strength of the Parliamentary forces into a disciplined and faithful organisation known as the New Model Army. The King surrendered, early in 1646. But though many in the Parliament wanted a new freedom for all and even a kind of Socialism, the main landowners were violently against these ideas and were even plotting with the King.

In 1648 Charles resumed the war, but was captured by the Scots. He was brought to London, actually being taken in by one of the leading Leveller soldiers; The King was Executed in January 1649. Cromwell then turned to deal with the Left-wing Idealists known as the Diggers and the Levellers.

The Levellers were small yeomen farmers and 'copyholders', tradesmen who worked in clothing manufacture, small business men - in fact skilled workers and peasants and the 'petty bourgeoisie'. A great number of them had fought in the New Model Army. Cromwell had encouraged his soldiers to be a committed, thinking force with intelligent discipline, but also with intelligent belief in God and in the new England they fought for. Discussion, argument and the printing and circulation of leaflets and tracts were encouraged.

It was this thinking and faith that brought Cromwell's army to victory over the Royalist army of foreign Mercenaries and estate Servants, pressed into service by their Lords and Landowners. The discussions continued during the lull, in 1647, between the two phases of the Civil War. There were perhaps as many civilian Levellers as military men, especially in London, where the leadership (Lilburne, Price, Walwyn and others) were based.