Defend the Realm

From its dramatic success during World War II through its turbulent Cold War-era upheavals to its work against terrorist suspects following 9/11, the exploits of Britain’s Security Service—MI5—have become the stuff of legend.

Defend the Realm marks an unprecedented publishing event: to mark the centenary of its founding, MI5 has for the first time opened its archives to an independent historian—Christopher Andrew, one of today’s foremost authorities on intelligence and espionage. Not only does it reveal the precise role of the Security Service in 20th-century Britain, it also details its history, its structure and many previously guarded secrets.

Following its formation in 1909 by Captain Kell of the British Army, during World War I the Service’s role centered around the identification of foreign agents, while after the war its focus shifted to security operations throughout the British Empire. With the onset of World War II, it achieved extraordinary success with its “double cross” program that offered enemy agents the chance to work on behalf of the Allies. But this era also saw the infiltration by Soviet Intelligence, which turned a group of Cambridge-affiliated agents—most notably Philby, Blunt, Maclean and Burgess. The success of the Soviet penetration haunted MI5 through the late 1980s, until the publication of Peter Wright’s international bestseller, Spycatcher. The book suggested that the “Cambridge Five” were not alone, and that others had infiltrated the services—most prominently Roger Harris, MI5’s director through much of the 1960s. Since then, the service has seen activity on a global scale, from identifying terrorist suspects in Malaysia, Kenya and Cyprus during the 1960s and 1970s to dealing with such homegrown threats as the IRA and Islamic terrorist cells.

Taking us beyond MI5’s storied past, Defend the Realm describes how the Service is managed, its relationship with the British government, and where it has triumphed and where it has failed. It also reveals the identities of previously unknown enemies of the United Kingdom whose activities have been uncovered by the Service. And above all, it shows the place of this previously extremely secretive organization within the United Kingdom. Adding to these rich revelations, the book features 32 pages of photographs, many of which are from the Security Service's archives and have never been published before. There are also approximately 25 documents within the text that illustrate various aspects of the Service's history.

A first-of-its-kind look behind a closely-guarded wall of secrecy, Defend the Realm makes an extraordinary contribution to our understanding of British history over the past century.