To mark the centenary of its foundation, MI5 opened its archives for the 1st time to an independent historian, resulting in an unprecedented publishing event. In The Defence of the Realm, Christopher Andrew reveals the precise role of the Security Service in 20th-century British history, from its founding by Captain Kell of the British Army in 10/1909, thru two world wars, & up to & including its present roles in counter-espionage & counter-terrorism. Readers will…