Eaton Square, in West London’s upmarket Belgravia district, has traditionally been home to the wealthy and well-known, from Raymond Chandler and W. S. Gilbert to Andrew Lloyd Webber and Barry Gibb. Writing about its storied history for my new book, The Secrets of Eaton Square, was therefore as much an opportunity to tear through London’s often troubled relationship with celebrity over the past two centuries as it was a chance to explore the changes and evolutions of the area. It amused me that, 60 or 70 years ago, artists and writers were wealthy enough to afford homes in the square. Now, with apartments—not houses—selling there for as much as $13 million, the neighborhood has removed itself from their grasp, and become instead a playground for the .01 percent.

Its present-day residents, however, are not as compelling or outrageous as its latter-day inhabitants. During my research for the book, I came across countless stories that would have seemed implausible if they had been storylines in Upstairs, Downstairs, the cult British television drama set in a lightly fictionalized Eaton Square. Britain’s doomed wartime prime minister Neville Chamberlain had a house there—at the same time as his political frenemies and rivals Lord Halifax and Stanley Baldwin—which he rented to the Nazi Joachim von Ribbentrop, who at the time was serving as Germany’s ambassador to Britain. Even before the outbreak of W.W. II, Chamberlain was aware of the irony of this, commenting to his sister that the tenancy was “amusing, considering my affection for Germans in general, and R. in particular.”