What is known as the oldest and shortest national constitution in the world?

The United States Constitution is recognized as the oldest written national constitution still in use today. It was ratified in 1788 and has remained largely unchanged over the years, distinguishing itself through its longevity and foundational role in establishing the framework for federal governance in the United States. Its brevity is another significant aspect, consisting of only seven articles which outline the structure of government, the powers of each branch, and the rights of the states.

While other constitutions exist, such as those of Japan, Canada, and Austria, they either did not originate first, or in the case of the Canadian Constitution, are derived from multiple documents, thereby making them more complex. The simplicity and clarity of the U.S. Constitution have allowed it to endure and adapt through amendments while remaining the shortest among similar national constitutions currently in use.