Top Secret Ultra

by Peter Calvocoressi

First published in 1980, this is one of the very few books written by someone who worked at Bletchley Park for much of the war. Its author was one of the team working in Hut 3, whose task was to translate decrypted German Army and Air Force signals, and assess their intelligence value. This new edition, while substantially rewritten and revised, remains a valuable personal account or personal experience.

Genres: History, World War II, Espionage, Nonfiction

158 pages, Paperback

First published January 1, 1980

Reviews

[Christopher Conroy · Rating 3 out of 5]

Extremely informative, but really, really dry. I had to just flip through it.

[Ken Nilsestuen · Rating 4 out of 5]

Overall I liked the book. A bit technical at the beginning, but later on I was able to understand Ultra better because of that introduction.

[Ushan · Rating 4 out of 5]

Peter Calvocoressi was born in Karachi, British India, in 1912, of Chiot Greek parents; he grew up in England and went to Eton and Oxford. In 1940 he volunteered for the British Army but was rejected because of a recent head injury. However, his coworker, a son of the Director of Intelligence at the Air Ministry, told him that the Royal Air Force was desperately short of intelligence officers, and he applied there, and was hired and given a one-way ticket to Bletchley, a town 50 miles northwest of London. Upon arriving, Peter Calvocoressi was astounded to learn that British intelligence was reading and decrypting German radio traffic. The decrypted intelligence was called Ultra, and had its own secrecy level, Top Secret Ultra. Peter Calvocoressi spent the rest of the war working as a cryptanalyst at Bletchley; later he was a lawyer and a political historian; in the 1970s he wrote a short history of Ultra and its role in the Second World war. The British knew that Germany was going to attack the Soviet Union in June 1941, and Churchill repeatedly warned Stalin about it, but Stalin seemed to have more trust in his fellow dictator. They also knew that Germany was going to counter-attack in the Ardennes in December 1944, but the Allied commanders disregarded this intelligence. The legend that Churchill knew that the Germans were going to bomb Coventry in November 1940, but decided to allow this to happen lest the Germans learn that their codes had been broken, has no truth to it, although it is popular in the Russophone blogosphere. Ultra intelligence was shared with the Americans, but not with the Soviets; Calvocoressi writes that from decrypted German communications, they learned that the Germans had broken Soviet codes, and that if the Ultra secret had been told to the Soviets, the Germans would have learned it too. Why not tell the Soviets that the Germans had broken their codes? One of the Cambridge Five spies, John Cairncross, was also at Bletchley during the war, and passed on to the Soviets the intelligence crucial for winning the Battle of Kursk, but this was not publicly revealed until after this book was published.

[Diane Henry · Rating 4 out of 5]

A nice little addition to the WWII corpus. Calvocoressi assumes the reader is familiar with the broad outlines of the war. I enjoyed the insider's look at decryption--he explained details that were missing from other books probably because the details are minuscule compared to the war itself. Well worth the read if one is already fairly familiar with WWII in general and Enigma/Ultra specifically.

[John · Rating 4 out of 5]

This was actually my first exposure to cryptography. After rescuing a bookshelf from being thrown out at my grandfather's, I found this book in the stack. A great book for someone wanting a perspective at Bletchly Park and the way the huts were run.

[Sister]

Still reading -- but awesome.

[Cynthia · Rating 3 out of 5]

interseting

ok

[Dave · Rating 4 out of 5]

Short but very detailed.