Calder Walton
Kennedy School of Government, Harvard University
Intelligence Historian | Barrister

Current Research

I am currently an Ernest May Fellow at the Kennedy School of Government, Harvard University, where my research is broadly concerned with intelligence history, grand strategy, and international relations in the twentieth century. My research has a particular focus on policy-relevant historical lessons for governments and intelligence communities today. Building on my previous research in the Faculty of History at the University of Cambridge (UK), I am presently collaborating to write a history of the UK-US ‘special’ intelligence relationship, from the Second World War to the War on Terror. As well as my research into intelligence history, I am also an English-qualified Barrister (litigation attorney) and mediator, practising in alternative dispute resolution. I help government and commercial clients resolve disputes through mediation, away from court, and am particularly interested in doing so through new forms of internet-based technology.

Previous Research and Work

Empire of Secrets

My first book, Empire of Secrets: British Intelligence, the Cold War and the Twilight of Empire, was published by Harper-Collins 2013. It was highly acclaimed and won the Longman History-Today book of the year award that year. See below for press reviews for Empire of Secrets.

Authorized History of MI5

While pursuing doctoral and post-doctoral research at Cambridge University, I was a principal researcher on Professor Christopher Andrew’s unprecedented (and best-selling) official history of the British Security Service (MI5), Defend the Realm. The Authorized History of MI5, published by Penguin in 2009 to mark MI5’s centenary anniversary. This research position gave me extraordinary insights into British intelligence history.

Legal Work

I trained as a barrister at the leading Chambers in the UK specialising in litigation and corporate insolvency, South Square Chambers, and after that, worked as an Associate in the Disputes department in the London office of a leading international law firm, White & Case. These positions gave me widespread experience on high-value litigation and international arbitration, often involving government and defence issues, and also regulatory investigations. Among other matters, I worked on significant claims arising from the bankruptcy of Lehman Brothers, the largest banking collapse in history; several disputes involving the UK Ministry of Defence; and represented an investment bank in UK/US regulatory investigations in multiple jurisdictions into the recent manipulation of the primary benchmark for short-term interest rates, the London Interbank Offered Rate (LIBOR).

University Education and Teaching

I received a PhD in History from Trinity College, Cambridge, which was fully-funded by the UK Arts and Humanities Research Council (AHRC), and after that was a post-doctoral Junior Research Fellow at Darwin College, Cambridge, funded by the Isaac Newton Trust at Cambridge. As a Junior Research Fellow, I was also a Member of the Governing Body of Darwin College, Cambridge.

During my post-doctoral research at Cambridge, I helped to teach and organise a course on intelligence history, which at the time was persistently the most popular undergraduate course offered in the Faculty of History at Cambridge. I also helped to coordinate the Cambridge Intelligence Seminar, arguably the most active academic intelligence seminar in the world.

Other Publications and Media

I have published widely on intelligence history in academic journals, book chapters, and the popular press. I serve on the editorial boards of several international journals and frequently review books for a variety of newspapers and literary journals.

Select journal articles and book chapters

  • “British intelligence, the Mandate of Palestine, and threats to national security immediately after the Second World war” Intelligence and National Security 23 (2008) pp.435- 62
  • “Torture and intelligence gathering in western democracies” History and Policy ( (Oct. 2008)
  • with Christopher Andrew, “Still the “missing dimension’: British intelligence and the historiography of British decolonization” in Patrick Major and Christopher Moran (eds), Spooked: Britain, Empire and Intelligence since 1945 (Cambridge 2009) pp.73-96
  • with Christopher Andrew, “The Gouzenko Case and British Secret Intelligence” in J. L Black and Martin Rudner (eds), The Gouzenko Affair: Canada and Beginnings of the Cold War (Penumbra, 2006)

Media and talks

I have published and presented my research in newspapers and on radio and television, on both sides of the Atlantic. I have given talks about my research at universities, policy institutes, government agencies, and literary festivals, both in Europe and the US. For speaking engagements, please see contact details below.

Praise for Empire of Secrets

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My first book, Empire of Secrets. British Intelligence, the Cold War and the Twilight of Empire, was published in hardcover in the UK by HarperPress in January 2013. It has been translated into numerous foreign languages.

It is the first book to reveal the largely untold activities of British intelligence in the last days of the British empire— the largest empire in world history, the decline and fall of which was pivotal not only in British history, but also in the history of international relations in the Cold War. As well as adding a new dimension to our understanding of Britain’s imperial history, the book also has striking resonances for the world today. It reveals the use and abuse of intelligence by governments in the past, ‘rendition’ during the Second World War, the use of torture during interrogations in counter-insurgencies, threats of terrorism and counter-terrorism, and the balance that western countries struck between security and civil liberties.

 Empire of Secrets is available from Amazon (hardcopy) (paperback) and other good retailers. It is also available for e-book download and to purchase on Kindle.

Empire of Secrets – was shortlisted for the ‘Debut Political Book of the Year‘ at the Political Book Awards 2014.

Empire of Secrets – won the prestigious Longman-History Today Book of the Year 2013 award.


Calder and his editor, Martin Redfern (William Collins), at the award ceremony for the Longman-History Today Book of the Year 2013, January 2013

“[an] intelligent, highly readable and fascinating historical account of the emergence of the secret state in Britain…Calder Walton is well suited to write such a book… He has used with great flair a mountain of top secret records…fascinating…He is a worthy and appropriate winner of this year’s [Longman-History Today] book prize.” Taylor Downing, History Today (March 2014)

“…thoroughly documented… fascinating reading.” Andrew Moravcsik, Foreign Affairs (January/February 2014)

“… an important and highly original account of postwar British intelligence… [which does] an excellent job of elucidating the part played by British intelligence in decolonization.” Daniel Johnson, Wall Street Journal Booskshelf (3 January 2014)

“… fascinating history of British intelligence… [with a] rich an fascinating analysis of the dissolution of the British Empire…” International Institute of Strategic Studies, (December 2013- January 2014)

“. . . for those interested in the Cold War, intelligence history, and British decolonization, the book proves indispensible.” Karl Wolff, New York Journal of Books (14 November 2013)

“This is a tremendously interesting and useful book – one that works as intelligence history and as colonial/imperial history.” Intelligence and National Security (01 August 2013)

“a long overdue book on the role of the intelligence services in Britain’s retreat from empire… [a] pioneering book on a very complex, and at times uncomfortable, aspect of  Britain’s postwar history….” International Affairs (July 2013)

“Fascinating… moves the spooks from the periphery of history to its heart… A well-documented, courageous and incisive first book by an author who has inhabinted the real world of intelligence rather than a James Bond fantasy… required reading.” Jimmy Burns, The Tablet (6 April 2013)

“tantalising…revealing and fascinating.” Bernard Porter, London Review of Books (21 March 2013)

“… competent, comprehensive and persceptive… It is one of those books that no student of the subject can ignore.” Alan Judd, The Spectator (2 March 2013)

“With fluency and judiciousness, he tells how Britain’s secret services responded to, then helped engineer and fine-tune, and later hushed up one of the most important historical events of the last century: Britain’s often hurried but generally orderly retreat from Empire… the history of Britain’s decolonisation will now begin to be rewritten. Walton’s first draft is acute, well-researched and agreeably lively.” Andrew Lycett, The Telegraph (25 February 2013) Book of the Week

“The overall effect is an entertaining and welcome demystification of the intelligence services and their role in the demise of Britain’s empire.” Josh Glancy, The Sunday Times (Culture) (17 February 2013)

“Walton’s prose bounds along, the nitty-gritty detail of intelligence leavened with occasional flashes of humour… Empire of Secrets is an important addition to the literature on decolonisation. It shines new light into the murky world of intelligence that underpinned the formalities of departure, the anthems and flag-lowering ceremonies, the wheeling parades and high-flown sentiments of nationalism.'” Richard Hopton, Financial Times (8 February 2013)

‘[a] superb and engaging account of the role of intelligence during the decline of Britain’s Empire.’ 4 stars, Rebecca Porter, Daily Express (3 February 2013)

‘There is enough human anecdote and eccentricity in Empire of Secrets’s “high octane” narrative to please even the most satiated consumer of such subjects [Nazis, the monarchy, class and spies]… [it is] a story that often left me wondering what on earth we pay these people for.’ Michael Burleigh, The Literary Review (February 2013)

‘a fascinating history of intelligence and empire. Walton’s book is perfectly timed, as Britain braces for a possible public inquiry into allegedly systemic torture of prisoners in Iraq. Walton provides appalling insight into the use of torture throughout the withdrawal from empire…’ Ed Vulliamy, Observer (31 January 2013)

“Walton is a very good writer. Empire of Secrets fairly rips along, summoning in places the verve of a good spy novel… It is to his credit that he has produced such a gripping, thoughtful and satisfying book on an aspect of British history still largely hidden by shadow” 5 stars, Dan Jones, Daily Telegraph (26 January 2013)

“…a compulsively readable tale of loss of empire, a necessary process of decolonisation overseen by MI5” Iain Finlayson, The Times (26 January 2013)

“Path-breaking and a very good read” Christopher Andrew

“People who believe there’s not much left to learn about the British Empire should read this book. Calder Walton has sculpted a fascinating study of where spy-craft touched palm and pine.” Peter Hennessy

“Empire of Secrets is an invaluable assessment of declassified intelligence records and an incomparable analysis of the cold war, colonial insurgency campaigns, and the British intelligence community itself” Wm. Roger Louis


I can be contacted at