General Hastings Ismay was one of Prime Minister Winston Churchill’s leading advisors during the Second World War and a “man who knew most of the secrets of the Second World War.” As chief of staff to the Minister of Defence and a member of the Chiefs of Staff Committee, Ismay worked on a daily basis with the prime minister, so much so that Churchill later wrote “we became hand in glove, and much more.” Avoiding taking a role in the formulation of military policy, Ismay, as the London Times noted, “conceived his role as being to run the machine which ran the war.” With his patience, tact, and friendly demeanor, he did so “supremely well.” After the war he served as a chief of staff to Lord Louis Mountbatten as the last Viceroy of India, chaired the Festival of British, and briefly served in Churchill’s post-war cabinet before being appointed the first Secretary-General of NATO. ‘Pug,’ Churchill’s Chief of Staff: The Life of General Hastings Ismay, KG, GCB, CH, DSO, PC 1887-1965 by Andrew Sangster is a short biography that covers Churchill’s relationship with his key subordinate. The author acknowledges that Ismay held the prime minister in great admiration, which actually to some historians veered close to hero-worship, and that Churchill was a difficult taskmaster.