The Levellers were an informal alliance of agitators and pamphleteers who came together during the English Civil War (1642-1648) to demand constitutional reform and equal rights under the law. Levellers believed all men were born free and equal and possessed natural rights that resided in the individual, not the government. They believed that each man should have freedom limited only by regard for the freedom of others. They believed the law should equally protect the poor and the wealthy. The Levellers were the social libertarians of the day (or classic liberals). "Leveller" was a term of abuse, coined by their opponents to exaggerate the threat of their ideas.
The main leader of the Levellers was John Lilburne (known as Freeborn John). Lilburne was a Lieutenant-Colonel in the Parliamentarian Army. Through his extensive writing and publishing of pamphlets, he was able to gain wide support for his ideas among army soldiers and the common people.
Lilburne "was, or became, a radical in everything — in religion, in politics, in economics, in social reform, in criminal justice — and his ideas were far ahead of his time. From 1637 when he was but twenty-three years old. until his death twenty years later, he managed to keep his government in a hectic state. In successive order he defied king, parliament, and protectorate, challenging each with libertarian principles. Standing trial for his life four times, he spent most of his adult years in prison and died in banishment. Yet he could easily have had positions of high preferment if he had thrown in his lot with Parliament of Cromwell. Instead, he sacrificed everything in order to be free to attack injustice from any source. He once accurately described himself as `an honest true-bred, freeborn Englishman that never in his life loved a tyrant or feared an oppressor.'"
— Levy, Leonard W., Origins of the Fifth Amendment, New York: Oxford University Press, 1968, p. 272.
In 1649, Lilburne published the "Agreement of the People", a manifesto for constitutional reform in Britain that gave birth to many of the ideas that are embodied in the U.S. Constitution and Bill of Rights.
This particular version was smuggled out of the Tower of London, where Lilburne and the others were being held captive.
All Leveller soldiers, and they were the majority in many regiments, carried this agreement proudly tucked into their hat-band. The agreement proposed a written constitution to define England's government, abolish arbitrary power, set limits to authority, and remove grievances.
Included in the Agreement of the People (1649):
Although the Leveller movement ended, and John Lilburne eventually died in prison, the ideas of the Levellers live on.