PHM is the national museum of democracy, telling the story of its development in Britain: past, present, and future.
On this blog we share posts from the PHM team and other experts, with behind the scenes stories, coverage of PHM's exhibitions and events, and highlights from the museum's unique collection.
Dr Claire Kennan, from the Department of History at Royal Holloway, University of London reveals the influence of unions stretching back to the Middle Ages.