London in the 1830s was undergoing great changes. In the streets old hackney coaches jostled with new omnibuses, night watchmen gave way to the new police, the poor crowded into inner-city slums, and the middle classes colonized genteel new suburbs. This was young Dickens's city, and he reported it all - the gin palaces, pleasure gardens, streets, shops, prisons, and law courts - as though he were, in Walter Bagehot's words, "a special correspondent for posterity." It was as a journalist that he first made his mark. His very first book, published when he was only twenty-four, was a collection of sketches that had first appeared in newspapers and magazines written under the pen name "Boz." Sketches by Boz was an instant bestseller. Dickens's knowledge of London was "extensive and peculiar" - like Sam Weller's in Pickwick Papers. "He knew it all, from Bow to Brentford," said one of his friends. In his Sketches the future novelist was marking out his territory, just as, in the pamphlet Sunday Under Three Heads, also included here, the lifelong campaigner against injustice and class oppression was finding his unique voice. This is the first of four volumes of Dickens's greatest journalism - the first ever annotated edition to be published.