The World's Oldest Constitutions, Some Lasting More Than 400 Years

A constitution serves as the primary foundation for the administration of a state. The document regulates the division of power, the system of government, and the rights of citizens.

Although nearly every country has a constitution, the age of each constitution varies greatly. Some are replaced within a matter of years, while others have managed to endure for hundreds of years through a series of amendments.

In practice, a long-lasting constitution does not mean it has remained unchanged. Most have been revised many times to adapt to political, social, and legal developments. What is maintained is the continuity of the constitutional framework as the basis for state administration.

San Marino ranks first as the country with the oldest constitution still in force today. The Statutes of the Republic of San Marino came into effect on 8 October 1600 and still serve as the foundation of the country’s legal system.

The document, written in Latin, consists of six sections regulating the structure of government, judicial institutions, and state administrative governance.

In 1974, San Marino added a Declaration of Citizens’ Rights, then updated it in 2002 without abolishing the constitution that has been in force since the 17th century.

The United States is next. Its constitution was ratified on 21 June 1788 after receiving approval from nine of the original 13 states.

The document is often referred to as the oldest codified national constitution still in force because all of its fundamental provisions are contained in a single legal text.

Since taking effect in 1789, the United States Constitution has undergone 27 amendments. The first ten amendments are known as the Bill of Rights, which guarantees various civil rights.

Poland follows with the Constitution of 3 May 1791, known as one of the first modern constitutions in Europe. The document introduced the separation of powers among the executive, legislative, and judicial branches.

Its period of validity was brief due to the Polish–Russian War of 1792. Nevertheless, the ideas introduced in the constitution influenced the development of constitutional law in various European countries. Poland’s current modern constitution came into force in 1997 and was last amended in 2009.

The wave of constitution-making then spread in the 19th century. Norway adopted a constitution in 1814 that established popular sovereignty, separation of powers, and protection of human rights as the state’s main principles.

The Netherlands built its constitution around 1814–1815 and carried out a major revision in 1848 that strengthened the parliamentary democratic system. Belgium, Luxembourg, Switzerland, Denmark, and Canada subsequently followed suit by establishing national constitutions that have been maintained through amendment mechanisms.

The endurance of constitutions over hundreds of years shows that a constitution’s resilience does not depend on the absence of change. On the contrary, the ability to adapt through amendments is the factor that keeps a constitution relevant to the times.

Data from the Comparative Constitutions Project even shows that the average age of constitutions worldwide is far shorter than that of the oldest group of constitutions.