Which British historical treaty or document shaped the nation most profoundly?

Sealed at Runnymede, it planted the idea that even monarchs answer to law. Its echoes still ripple through constitutional thinking worldwide.

This parliamentary marriage created a single kingdom and a shared destiny. Its consequences are still hotly debated north of the border today.

Following the Glorious Revolution, it curbed royal power and entrenched parliamentary sovereignty. Much of our modern democratic framework rests on its foundations.

Britain helped shape the post-Great War settlement that punished Germany and reordered empires. Its flaws arguably set the stage for another devastating conflict.

A painstaking compromise that ended decades of bloodshed in Northern Ireland. Its delicate balance remains tested by Brexit and shifting politics.