It is impossible to imagine London without the Tube: the beating heart of the city, the Underground shuttles over a billion passengers each year below its busy streets and across its leafy suburbs. The distinctive roundel, colour-coded maps and Johnston typeface have become design classics, recognised and imitated worldwide. Opening in 1863, the first sections were operated by steam engines, yet throughout its long history the Tube has been at the forefront of contemporary design, pioneering building techniques, electrical trains and escalators, and business planning. Architects such as Leslie W. Green and Charles Holden developed a distinctively English version of Modernism, and the latest stations for the Jubilee line extension, Overground and Elizabeth line carry this aesthetic forward into the twenty-first century. In this major work published in association with Transport for London and now updated, Tube expert Oliver Green traces the history of the Underground, following its troubles and triumphs, its wartime and peacetime work, and the essential part it has played in shaping London's economy, geography, tourism and identity. Specially commissioned photography by Benjamin Graham (UK Landscape Photographer of the Year 2017) brings the story to life in vivid portraits of London Underground's stations, tunnels and trains.