The future of the Union is today at greater threat than at any time in living memory. In this series David Olusoga uncovers the long history of union and disunion, tracing their origins back centuries.

The fracture lines of our current division run along the borders between the 'home nations' but we are also disunited by social class and inequality, by England's north-south divide and the historic dominance of London. Our disunity can be told through the historic rise and fall of what are today called 'left-behind towns' and the long history of our rural-urban divide.

David's own personal experience connect him to several regions of the UK, each with their own strong identities. He grew up in a working-class community in the North East of England, a politically independent region with an antipathy towards London. And as a mixed-race child who came Britain in the 1970s, he has seen for himself how complex and nuanced the relationship between the individual and the nations of the UK can be.