Conel Hugh O'Donel Alexander

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Conel Hugh O'Donel Alexander (born April 19, 1909 in Cork , † February 15, 1974 in Cheltenham ) was a British chess master . During the Second World War he contributed significantly to the deciphering of the German rotor key machine Enigma .


Hugh Alexander's father was a professor at the University of Cork. After Hugh was born, he was called to Birmingham , where he moved with his family. After graduating from school, Hugh studied mathematics at Cambridge with a master's degree . From 1932 to 1938 he taught mathematics at Winchester College. His eldest son Michael Alexander won an Olympic silver medal in fencing and was British ambassador to Austria .


Memorabilia by Hugh Alexander and Herbert Murrill in Bletchley Park, Alexander's pocket chess game in the upper left

Hugh started playing chess at the age of eight. In 1926 he won in Hastings , the British Youth Championship ( British Boys Championship ). During his studies at Cambridge he won the university championship four times. In 1937/38 he finished second at the Hastings Premier together with Keres behind Reshevsky . He won the tournament in 1946/47. In 1950 he became international champion , in 1953/54 he was first in Hastings together with Bronstein . He took part in several British championships and won them in 1938 and 1956. In the Chess Olympiads 1933 , 1935 , 1937 , 1939 , 1954 and 1958 Hugh was part of the English team, while he achieved the third-best individual result of the reserve players at the Chess Olympiad in Folkestone in 1933 .

In the late 1960s he began to play correspondence chess with success and was named International Correspondence Chess Master in 1970. He took part in the 6th and 7th Correspondence Chess Olympiad .

He was the first chess columnist for The Spectator and wrote under the pseudonym Philidor .

His best historical rating was 2610, which he achieved in March and April 1955.

Bletchley Park

The legendary "Hut 6" (photo from 2004) in Bletchley Park, where Alexander worked on deciphering the German Enigma in 1940.

Hugh Alexander was in 1939 as the reigning British chess champion along with his teammates Stuart Milner-Barry and Harry Golombek in Argentina when in Buenos Aires held Chess Olympiad . While the tournament was in progress, the participants were surprised by the outbreak of World War II after Great Britain declared war on the German Reich on September 3, 1939 in response to the German invasion of Poland . Alexander and his team-mates then canceled the tournament and immediately returned to England.

In February 1940, Alexander joined the so-called Government Code and Cypher School (GC&CS) (German: "Staatliche Code- und Chiffrenschule"), which was located about 70 km northwest of London in Bletchley Park . It was a camouflage designation for the military service that successfully deciphered communications during the Second World War, which the German military encrypted with their Enigma key machine.

Alexander initially worked in the Hut Six (German: "Baracke 6"), where, under the direction of Gordon Welchman, they worked on the deciphering of the German Army and Air Force radio messages. In 1941 he switched to Hut Eight (German: "Baracke 8") and advanced to the position of Deputy (English: "deputy") of Turings. In contrast to Hut 6 , the British code breakers dealt there specifically with the deciphering of radio messages from the German Navy , which were encrypted with the Enigma-M4 key machine .

To decipher them, they used a method that has been known and proven for centuries, namely the "Probable Word Method" (see also: Pattern Search ). Here the attacker guesses, suspects or knows that a certain phrase (English crib, French mot probable) appears in the text, for example "OBERKOMMANDODERWEHRMACHT". This "crib" (probable word) is used to set an electromechanical deciphering machine, called the Turing bomb , which was invented by Alan Turing , and with its help to find the unknown roller position and basic position chosen by the German encryptors for encryption had.

Alexander was housed near their place of work together with Milner-Barry, who was busy in the neighboring department Hut 6 with similar tasks, but in connection with the German Army Enigma. Their long-standing acquaintance contributed to a very cooperative cooperation between the two departments and also helped to avoid conflicts in the allocation of the very limited "computing time" of the Turing bombs.

In the fall of 1941, Bletchley Park suffered from a severe staff shortage, which delayed the Enigma decipherments. The GC & CS management seemed unable to solve this problem. As a result, the bosses of Hut 6 , Gordon Welchman, and Hut 8 , Alan Turing, together with their deputies, Milner-Barry and Alexander, decided to bypass the official channels and to contact British Prime Minister Winston Churchill directly . Churchill, who was fully aware of the importance of the decipherments, responded with his now legendary instruction: " Action this day: Make sure they have all they want on extreme priority and report to me that this has been done " (German: "Do you still act." today! Make sure you get everything you want with the utmost priority and report to me when that is done. ")

The British code breakers from Bletchley Park succeeded in maintaining the Enigma's deciphering ability for the entire duration of the war, with the exception of a few interruptions , and thus contributed significantly to the rapid victory of the Allies . After the end of the war, Alexander remained in the British Foreign Office.


  • Friedrich L. Bauer : Deciphered Secrets. Methods and maxims of cryptology. 3rd, revised and expanded edition. Springer, Berlin et al. 2000, ISBN 3-540-67931-6 .
  • Francis Harry Hinsley , Alan Stripp: Codebreakers - The inside story of Bletchley Park. Oxford University Press, Reading, Berkshire 1993, ISBN 0-19-280132-5 .
  • Sir Stuart Milner-Barry: A Tribute to Hugh Alexander. in: Harry Golombek and William Hartston: The Best Games of CH O'D Alexander. 1976, pp. 1-9. PDF; 12 kB
  • Gordon Welchman : The Hut Six Story - Breaking the Enigma Codes. Allen Lane, London 1982; Cleobury Mortimer M&M, Baldwin Shropshire 2000, ISBN 0-947712-34-8 .

Web links

Individual evidence

  1. ^ Conel Hugh O'Donel Alexander at , accessed on September 12, 2019.
  2. Conel Hugh Alexander's results at the Chess Olympiads on (English)
  3. Luke McShane : Visky business , The Spectator, October 5, 2019