A number of people have helped to bring this book to fruition. Thanks to Laurent de Sutter for initiating the project and to the team at Polity for bringing it all together – George Owers, Neil de Cort, and Manuela Tecusan. Alex Andrews was an immensely helpful technical advisor, and thanks to everyone else who read earlier drafts – Diann Bauer, Suhail Malik, Benedict Singleton, Keith Tilford, Alex Williams, and two anonymous reviewers. Last but not least, thanks to Helen Hester for supporting me and for always being my most intellectually challenging and insightful critic.