PBS: Premieres: Wednesday 1 April at 7.15pm

This is the human story behind the greatest construction project of all time –a structure thousands of miles long, built with the blood and sweat of countless people. The Great Wall of China symbolises the achievements not just of one nation but of all humanity.

What we know about the wall is always changing. How was it built? How did it operate? And how did people live on it? We thought we knew the answers to these questions, but recent discoveries have cast this man-made marvel (twice as long as once thought) in a new light.

This film recreates the building of the wall through the eyes of its instigator, an ordinary worker and a court politician, and draws on modern research to reveal little-known facets of its history.