Walk down any street in London and pause for a moment. To your left and right is an array of doors in different styles and colours. Craftsmen across the centuries have sought to impress you with elegant designs. Owners have added their own finishing touches, a hand-painted pattern here, a Shakespeare door knocker there.The front door is the focal point of a building. It draws the eye of the visitor and conveys the status and aspirations of the occupants, enhanced with a brass name plate, perhaps, a heraldic shield or a Latin inscription. Past generations have often left nostalgic traces of their presence: a ring for tying up horses, a boot scraper to clean off mud and dung, a gas lantern. The authors have researched the stories behind the doors, revealing where Dr Johnson wrote his Dictionary, where Oscar Wilde was arrested or where Mrs Simpson visited the Prince of Wales.