History Internal
Assessment
Research
Question:
To what extent did the breaking of
the enigma code lead to the British and their allies winning the battle of the
Atlantic?
Plan of
investigation:
The focus of this
investigation will be “To what extent did the breaking of the enigma code lead
to the British and their allies winning the battle of the Atlantic?”, and it
will determine to what extent this was the main reason for the victory.
The aim of this investigation is to determine how British used the
information from the enigma to infiltrate the German’s plans for the battle of
the Atlantic in February of 1940, thus allowing them to win the battle (Sheffield, The Battle
of the Atlantic). This essay will focus on the time frame from
when the enigma code was cracked to when the battle of the Atlantic ended. This
question is important as it proves how important the breaking of the enigma
was, but also how this potentially contributed to the end of the war. To
determine this, this essay will look at a mix of sources, including information
from the Bletchley Park museum in England but also from modern day historians
that focused on Bletchley park and the Enigma code.
Identification
and evaluation of sources:
Source 1:
An extract from Winston Churchill’s “The Second World War Volume 2: Their Finest Hour”
This book was
published as volume 2 of Churchill’s 6 volume set. With the focus of this
volume being how the British fought the Germans. The official author is Winston
Churchill however he had help from many historians while writing the books. Winston
Churchill was prime minister of Britain during the war, which should mean he
had insight into the breaking of the enigma code and the effect that this had.
However, he was also under the official secrecy act meaning he couldn't reveal
all of the information he knew. The fact that the volumes have many authors can
be taken as both an advantage and disadvantage, it may mean that the views that
are presented can be mixed and not necessarily the official views of Winston
Churchill. It was published in 1948, just a few years after the end of the war,
this means some events that happened during the war were not common knowledge
for the British people. Due to Britain and her allies having won the and
Churchill is heavily biased in his views. This influences the way in which the
arguments are presented however does not stop the book being of value to
historians.
Source 2:
An
extract from the book Seizing the Enigma: The Race to Break the German
U-Boat Codes, 1933-1945 by American
historian David Kahn
The
author of this book is an American Historian named David Kahn, the world’s
leading expert on the history of cryptography.
This can be seen as value as he has a good knowledge of the subject that
he writes about. As it is a book it is written from the point of view of the
author, which could mean his writing is biased. Written and published in 1967,
after the end of the war, it meant that he was writing with hindsight, and he
was able to write with having knowledge of how the war ended. However, despite
this, many of the documents regarding the breaking of the enigma code were not
available or disclosed after the end of the war, so how much information he was
actually able to gain access to is difficult to evaluate. The book focuses on
breaking of the enigma code, which is an advantage as it means the topic was
well researched before the book was written and the author was able to consider
many different aspects rather than just looking quickly at one point. However,
he does not focus on Britain to be credited as the first country to crack the
enigma code, but rather the Soviet Union. However, it is not possible to say
whether this decision was due to lack on information being available on the
cracking of enigma at Bletchley park. The content of the book is also important as
Kahn makes his argument clear, he proves his point of view that “code breaking
neither won nor decided the war” saying it was only a secondary factor.
Investigation:
During the Second World War the opposing countries were fighting
many different battles. In order to protect their forces, it was imperative
that the plans were kept secret. Therefore, transmission communication was encrypted.
For the Germans this method of encryption was called enigma. At the time enigma was described as
unbreakable, as it was the best coding and encryption that could be used. The
only way to break enigma code was to know the exact code that had been used,
these codes changed every day meaning even if the enigma code was broken one
day, the process would have to start again the next day. There were teams of
people employed by the British Government at Bletchley Park to crack the Enigma
code. Bletchley Park was a large secret within the British government at the
time. However, after many years of working on it Professor Alan Turing broke
the Enigma code that meant that all German messages could be read and
translated by the British. Breaking the
code did not only have an effect on the battle of the Atlantic, but on the
outcome of the war as a whole. However,
this is will focus only on the effect of the breaking the Enigma code had on
the outcome of the battle of the Atlantic.
The battle of the Atlantic was not the only part of the war which
was effected by the breaking of the enigma. However, this essay will focus only
on the battle of the Atlantic as this was one of the crucial battles during
world war two and the victors would gain control of the seas, something that
could be devastating to the UK as they relied on the see to transport in
supplies such as food. The problem was highlighted in early 1941 when the
British navy was struggling to sink the German U-boats, allowing. This meant
Churchill was forced to create a Battle of the Atlantic emergency committee
(Sebag Montefiore,
93). This is something that is not included in Churchill’s own memoirs. However,
David Reynolds argues in his own book focusing on the background behind the
books written by Churchill, that this was not Churchill’s wish, but rather that
he was not allowed to publish anything about the breaking of the code as this
would “break the silence”, something the London Signals Intelligence center
would not allow (David Reynolds, 147).
The level of influence of the breaking of Enigma code is disputed by
historians. The true effect of cracking the Enigma code is unmeasurable,
however as Hugh Sebag-Montefiore argues in his book Enigma: the battle for the code the breaking of the enigma code
completely transformed the outcome of the battle of Atlantic (Sebag-Montefiore, 142). However, he also
makes evident just how the information that was discovered by decoding each
message was used. Once the code was cracked each message was translated. The messages
contained the details of the location or path of one of the German ships. This
information could then be used by the British to plan an attack on the German
ships and avoid their own ships getting attacked. Now some historians claim
that Enigma had little effect on the outcome and that the battle would have
been won anyway by the allies. In June of 1943 after Enigma was broken there
was a significant decrease evident in the amount of allies ships that were
sunk. As Turing himself talks about this
in his book The Essential Turing
the breaking of Enigma was so successful that for 23 days straight the
information that was provided by Hut 8 at Bletchley park allowed re-routings to
stop the north Atlantic U-boats from sighting a single convoy (Turing, 262). This means that the information was used in order to rearrange the path
of the British ships in order to help marginalize the amount of accidents.
Unlike Sebag-Montefiore,
Andrew Hodges focuses on the direct effects of the breaking of Enigma on the
German army rather than just on the British navy. As the British army were now
able to translate and make sense of the messages that were being sent by the
Germans meant the British army could now predict where the German ships where
going to be and thus plan an attack based on facts. Hodges states “Alan Turing’s
work had denied the ocean lanes to Germany”, this was a key part to Britain
being able to win the battle. The ocean lanes that he is referring to in the
quote is power over the oceans, having control of the oceans does not just mean
that Germany is able to attack Britain but also that it is able to control the
ships importing and exporting things to Europe (Hodge, 263).
Not all historians
agree on just how essential the breaking of enigma was on the outcome of the
battle of the Atlantic. Jonathan Dimbleby argues “Bletchley park’s contribution
to the battle of the Atlantic – though far from negligible – was at best
spasmodic and therefore significantly less critical to the outcome of the
struggle than in other theaters” (Dimbleby, 399) Although he does not deny that Bletchley had some effect
he just argues how much affect this actually had. He almost dismisses it,
giving it very little credit compared to other historians. This is important
when considering his entire book is based only on the battle of the Atlantic,
thus showing he clearly feels there is another, much more significant reason,
the allies won the war. There is also large controversial argument
between historians regarding how the information was used. Some argue that they
did not act on all the information, this was to make sure the Germans did not become
suspicious. Had this happened the British would risk the Germans changing their
code and they would be back at square one regarding knowing the attacks planned
against them. Because of this some historians argue that it is not possible to
truly determine how much effect the breaking of the code actually has. This
idea is backed by David Kahn, as he writes in his book that the breaking of the
code did not decide the outcome of the war. Therefore. both historians agree
that cracking enigma, while was not completely obsolete, was not the reason
that Britain and her allies won the war.
Assessing the facts
that have been presented and the views of the historians it is clear that all agree
that the cracking of the Enigma code contributed to the success of the battle. The fact that much of the evidence regarding
what happened at Bletchley Park was destroyed means that it is not possible to
determine the true extent the cracking of the enigma code had. Although most of
what occurred at Bletchley park is now accessible to the public, through the
archives or at the museum, it is still not known exactly what occurred.
Crucially this essay does not focus on the other battles that Britain fought against
Germany and won. Britain’s navy had been built up and expanded for many years
before Germany's and was therefore much stronger. In order to calculate how much
of the victory was based on England being able to plan attacks on the Germans
already knowing where they would be one must first know exactly how much chance
Germany had a beating the British in the first place. Breaking the Enigma code
may not have been the only reason that Britain won the battle, but it
definitely brought the battle to an end sooner than without and allowed Britain
to suffer significantly fewer casualties.
Reflection:
Completing
this investigation has allowed me to use a variety of different investigation
methods, however it also brought up issues in the investigation that I did not
foresee. One of these issues was the fact that all the work on enigma was kept
confidential under the official secrecies act. At the start of the
investigation I assumed one of the best sources would have been Winston
Churchill’s series of books “the Second World War Volume”, as these were
written by Winston Churchill who was prime minister of the UK during the war.
However, in these books there is no mention of enigma as he was also not
allowed to disclose this information.
My
trip to Bletchley park was also not as useful as I had first imagined it would
have been. Bletchley park had only a small section on the battle of the
Atlantic, and the rest mainly focused on Alan Turing and what the individual
sheds did towards the cracking of the enigma code. One of the reasons for this
is that some of the information from Bletchley park was destroyed during and
after the war, in order to keep it a secret.
Because
of these it meant my investigation had to rely more on secondary sources then I
had originally intended. However, this is an area that was researched a lot by
historians so there is a lot of information available. In comparison to
Churchill’s books, David Kahn’s book “Seizing the Enigma: The Race to
Break the German U-Boat Code” had a lot
more information despite being published years after the end of the war.
However, he does not give much credit to the British for cracking enigma.
Overall despite not being able to
rely on the resources I originally intended to, I found that there was enough
information to answer my research question.
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