A constituent assembly (sometimes also known as a constitutional convention or constitutional assembly) is a body composed for the purpose of drafting or adopting a constitution. As the fundamental document constituting a state, a constitution cannot normally be modified or amended by the state's normal legislative procedures; instead a constituent assembly, the rules for which are normally laid down in the constitution, must be set up. A constituent assembly is usually set up for its specific purpose, which it carries out in a relatively short time, after which the assembly is dissolved.
Unlike forms of constitution-making in which a constitution is unilaterally imposed by a sovereign lawmaker, the constituent assembly creates a constitution through “internally imposed” actions, in that members of the constituent assembly are themselves citizens, but not necessarily the rulers, of the country for which they are creating a constitution. As described by Columbia University Social Sciences Professor Jon Elster:
Constitutions arise in a number of different ways. At the non-democratic extreme of the spectrum, we may imagine a sovereign lawgiver laying down the constitution for all later generations. At the democratic extreme, we may imagine a constituent assembly elected by universal suffrage for the sole task of writing a new constitution. And there are all sorts of intermediate arrangements.
During the French Revolution (from July 1789 to September 1791) a National Constituent Assembly (Assemblée nationale constituante) was formed when representatives assembled at the only location available – a tennis court – and swore the Tennis Court Oath on June 20, 1789, promising that they would not adjourn until they had drafted a new constitution for France. Louis XVI recognized the validity of the National Constituent Assembly on June 27, 1789.
On 27 November 2010, Iceland held an election for a constitutional assembly, with 522 people vying for 25 delegate seats.
The Constituent Assembly of India was elected to write the Constitution of India, and served as its first Parliament as an independent nation. It was set up as a result of negotiations between the leaders of the Indian independence movement and members of the British Cabinet Mission. The constituent assembly was elected indirectly by the members of the Provincial legislative assembly, which existed under the British Raj. It first met on December 9, 1946 in Delhi. On August 15, 1947, India became an independent nation, and the Constituent Assembly started functioning as India's Parliament. Dr. Ambedkar drafted the Constitution of India in conjunction with the requisite deliberations and debates in the Constituent Assembly. The Assembly approved the Constitution on November 26, 1949, and it took effect on January 26, 1950 -- a day now commemorated as Republic Day in India. Once the Constitution took effect, the Constituent Assembly became the Provisional Parliament of India. (It was "provisional" until the first elections under the new Constitution took place, in 1952. The whole process took 2 years,11 months and 18 days from start to finish..
The Constituent Assembly of Italy was established in 1946 in the wake of Fascist Italy's defeat during World War II. It was elected with universal suffrage, simultaneously with a referendum about the adoption of Republic or the continuation of monarchy. Voters chose Republic, and the new assembly had the task to approve the new republic governments, as well as to write a new constitution. This was approved on 22 December 1947.
It was dissolved on 31 January 1948, to be replaced by the new Parliament of Italy.
United States 
The most famous constituent assembly in U.S. history was the Federal constitutional convention that drafted the still-current Federal Constitution in 1787. Unlike most constitutions, the U.S. constitution may be amended by Congress, although not as part of its normal business; again unlike other constitutions, amendments do not change the text of the constitution but are appended to it. While there is provision for calling one, no federal constitutional convention has been called. In part this is due to Congress being able to amend the constitution without a convention, and the daunting requirements for holding a new constitutional convention (requiring the consent of two-thirds of the States), but also because of the fear that wholesale changes in the Federal Constitution might undermine a document that has stood the test of nearly 225 years.
A rich tradition in the use of constituent assemblies exists at the state level of Constitutionalism. In fact, constituent assemblies met in the states before the formation of the Federal Constitution in 1787 as well as after its ratification. Since 1776 nearly 150 state constitutional conventions have met to draft or revise state constitutions.
These early state constitutional conventions frequently did not use procedural steps like popular ratification that became commonplace in the mid-19th century. Yet they were considered to be constituent assemblies that exercised their authority as that of the people. As American Sovereigns: The People and America’s Constitutional Tradition Before the Civil War by Christian G. Fritz notes:
“A legitimate constitution depended on whether the sovereign people authorized it, not whether a particular procedure was used or whether revolutionary conventions were free of other responsibilities, such as passing ordinary legislation. It was the people as the sovereign who authorized drafting those first [state] constitutions that gave them their legitimacy, not whether they used procedures that matched what was later understood to be necessary to create fundamental law.”
American state constituent assemblies in the 19th and 20th centuries reflected many qualities of a citizen’s movement. From the start of state American constitution-making, delegates to constitutional conventions studied earlier state models of constitutions. They often self-consciously "borrow[ed]" constitutional text and provisions from other states. They often used in their drafting and debates compact and pocket-sized compilations of all the existing American constitutions, so that the constituent’s assembly could draw upon the latest in constitutional design.
Countries without an entrenched constitution 
A few countries do not have an entrenched constitution which cannot be amended by normal legislative procedures; the United Kingdom, New Zealand and Israel are examples. In these countries there is no need to call constituent assemblies, and no provision to do so, as the legislature can effectively modify the constitution. If such a country decides to implement a constitution, presumably some sort of constituent assembly will have to be set up for the purpose.
The constitution of New Zealand consists of a collection of statutes (Acts of Parliament), Treaties, Orders-in-Council, Letters patent, decisions of the Courts and unwritten constitutional conventions. Because it is not supreme law, the constitution is comparatively easy to reform, requiring only a majority of Members of Parliament to amend it.
See also 
- List of constituent assemblies
- Convention parliament
- Constitutional convention (political meeting)
- Constituent Cortes
- National Constituent Assembly
- Third Dáil, also called the Constituent Assembly
- Id. at 125
- Axel Hadenius, ed., Democracy’s Victory and Crisis, Ch 7: Ways of constitution-making by Jon Elster (p. 123); Cambridge University Press, 1997. 431 pp [ISBN 9780521573115]
- See The Records of the Federal Convention of 1787 (Edited by Max Farrand; revised edition in Four Volumes, Yale University Press, 1966).
- Kermit L. Hall, Harold M. Hyman, and Leon V. Sigal, eds., The Constitutional Convention as an Amending Device (The American Historical Association and The American Political Science Association, 1981).
- Albert L. Sturm, “The Development of American State Constitutions,” 12 Publius (1982), 57-98.
- Marc W. Kruman, Between Authority and Liberty: State Constitution Making in Revolutionary America (Univ. of North Carolina Press, 1997), 1-33; Christian G. Fritz, “Alternative Visions of American Constitutionalism: Popular Sovereignty and the Early American Constitutional Debate,” 24 Hastings Constitutional Law Quarterly (1997), 322-29; Christian G. Fritz, American Sovereigns: The People and America's Constitutional Tradition Before the Civil War (Cambridge University Press, 2008) at p. 31-35 [ISBN 978-0-521-88188-3]
- Fritz, American Sovereigns: The People and America's Constitutional Tradition Before the Civil War (Cambridge University Press, 2008) at p. 33 [ISBN 978-0-521-88188-3] For more on the role of the requirement of complying with specific procedures and processes, see Christian G. Fritz, "America’s Unknown Constitutional World," Bonus Article, Common-Place, Vol. 9, No. 1 (Oct. 2008)</a>
- Laura J. Scalia, The Remaking of State Constitutions: The Uses of Liberalism in Designing Electoral Laws, 1820-1850 (Northern Illinois Univ. Press, 1999); John J. Dinan, The American State Constitutional Tradition (Univ. Press of Kansas, 2006).
- Marsha L. Baum and Christian G. Fritz, “American Constitution-Making: The Neglected State Constitutional Sources,” 27 Hastings Constitutional Law Quarterly (2000), 199-242.