Which country of the world has the oldest written constitution still in force today?

While many nations draw on ancient legal traditions, the document that holds the title of the oldest written national constitution in continuous use was drafted in 1787. Ratified in 1788 and taking effect in 1789, the Constitution of the United States established the framework for a new federal republic. Its key distinction is that it is a single, codified text intended from the start to be the supreme law of the land, a revolutionary concept at the time.

This model stands in contrast to that of other nations, such as the United Kingdom, which operates with an uncodified constitution. The British system of governance is not contained in one document but is instead derived from a collection of sources, including historic charters like the Magna Carta, various acts of Parliament, and long-standing conventions. While many of these sources are much older, they do not form a single, cohesive constitutional text.

The U.S. Constitution’s remarkable longevity is often credited to its design. By creating a durable framework for governance while also including a formal process for amendments, the founders built a document that was both stable and adaptable. This combination of rigidity and flexibility has allowed it to remain the nation's fundamental law for over two centuries, influencing the