As a partner in the British Empire, Scotland began the 20th century with an advanced economy and a world-beating heavy industry. But in the closing decades its sense of Britishness was in doubt and a Scottish Parliament sat in Edinburgh for the first time since 1707. Charting Scotland's darkest century, Neil Oliver discovers a country driven to self-determination through a series of economic crises so deep that her most striking export became her own disillusioned population.