The best way to approach Paddington is from its Underground station. You struggle through the anonymous, crowded, low-ceilinged subways, and through a ticket barrier: stairs and an escalator loom ahead; suddenly there is an arched roof high above and as you ascend the staircase the whole tremendous interior reveals itself. On a fine day as you stand in the middle of the broad central span, light floods in from the 'lawn' roof behind and, almost 700 feet away, the delicate tracery at the far end is silhouetted. The milling crowds, the long perspective, the waiting trains and the light in the distance produce an atmosphere of expectation: the experience of travel is heightened here in a way that few other British stations can match. It is one of the great interiors of London. Paddington, the Great Western Railway and their principal designer Isambard Kingdom Brunel are at the heart of railway history. Railways were one of the defining phenomena of Victorian Britain and one of Britain's many great gifts to the world, so the building of the GWR has a place in world history. This history forms the background to this book. It is an account of the station that epitomises the GWR and its operations, but which is also an important work of architecture.