I am grateful to my cherished editors – Sam Humphreys at Picador and Starling Lawrence at Norton – and readers: Gill Coleridge of Rogers, Coleridge and White, Melanie Jackson of the Melanie Jackson Agency, Alison Robb, Stephen Roberts and Margaret, who appears as a protagonist but is present on every page. I would also like to thank the following people and institutions: Morgan Alliche, Paul Baggaley, Ian and Ruth Bird, Nicholas Blake, Wilf Dickie, Camilla Elworthy, David Fawbert, Sudhir Hazareesingh, James Hiddleston, Henry Johnson, Cara Jones, Andrew Kidd, Laurence Laluyaux, Josine Meijer, David Miller, Claude and Vincenette Pichois, Gerald Sgroi, Peter Straus and Isabelle Taudière; the Social Science Library, the Taylor Institution and the History Faculty Library of Oxford University, the Bodleian Library, the Bibliothèque Nationale de France, the Bibliothèque Historique de la Ville de Paris, the Musée Carnavalet, the Institut Géographique National, the Club des Cent Cols and the RATP.