Peter Frederick Egerton Elstob (22 December 1915 – 21 July 2002) was a British soldier, adventurer, novelist, military historian and entrepreneur. In his writing he is best known for his lightly-fictionalized novel "Warriors For the Working Day" (1960) and his military history of the Battle of the Bulge, "Hitler's Last Offensive" (1971). He joined the Republican Army in the Spanish Civil War, and later served in the Royal Tank Regiment in World War II, in which service he was promoted to sergeant and was Mentioned in Dispatches. He joined International PEN in 1962 and served first as general secretary and later as vice-president for seven years during the 1970s, rescuing the organisation from financial failure; he also secured the future of the Arts Theatre Club in London in 1946. He prospered as an entrepreneur with a facial product called Yeast Pac, with several partners. In his obituary in The Guardian newspaper, Elstob was said to be