For historian and MP Rory Stewart, the building of Hadrian's Wall was the single most important event in Britain's history. Meeting experts and local people, and drawing on memories from his life in Iraq and Afghanistan, he explores the impact of Rome's occupation and departure, and tells the story of how the powerful new Kingdom of Northumbria was born in Britain's lost Middleland.

Hadrian's Wall cut a deep scar across Britain that would never be forgotten. A thousand years after the Romans left, the island split once again, near the line of the wall, into the Kingdoms of England and Scotland. Historian and MP Rory Stewart tells the story of how Britain was torn in two. The border country dividing Britain's lost Middleland became a zone of anarchy, as violent as border areas in the Balkans, Iraq and Afghanistan.