In April 1940, when Hitler was victorious in a blitzkrieg against Poland and was gathering troops and air forces to invade Belgium, the Netherlands, Luxembourg and France, the British spy agencies on the European continent were in a state of disintegration, fleeing, scattered, and most of the spies who were too late to leave and hid on the spot also lost contact. Britain at this time desperately needed to know every plan, every action, every order of the enemy. At this critical juncture, the "messenger" from Bletchley spoke, and he announced that "Eltra" had officially entered the war. Because they broke through the German "Enigma" cryptography system, they had intercepted and deciphered important information of the German army. "Drilling into the brains of the enemy" is no longer an illusion.
This achievement was hailed by Churchill as the most valuable secret of the war, and it was the result of the painstaking efforts of thousands of people, in addition to the British, even Poles, French...
So what exactly does "Eltra" mean?
"Eltra", a transliteration of the English word "ULTRA", also known as "superclassified", represents highly classified intelligence obtained by British intelligence agencies during World War II by intercepting and deciphering German radio codes.
About 80 kilometres northwest of london, the capital of The United Kingdom, there is a patchwork of Victorian architecture. It is located in Buckinghamshire, between the Universities of Oxford and Cambridge. A gloomy-looking mansion rises from the ground, and the surrounding Neeson cottages fill the entire estate.
This is the British code-breaking center known as the "Codebreaking Command", Bletchley Manor, which the staff affectionately calls "Cloth Village". It is also home to the British Government Crypto School (founded by Sir Hall during the First World War) and is headed by Lieutenant Colonel Alastair Denniston.
The Bletchley Estate is home to a large number of outstanding talents, including elites in almost all fields - mathematicians and philosophical figures, electrical engineers, radio experts, German experts and other foreign language experts, bank clerks, museum directors, chess champions and square anagram filling experts... At most, the staff reached 10,000 people, which were mathematical.
Most of these people are young people aged 25-30, from middle-class families, well-educated, and many are university professors. A considerable number of people behaved strangely, with long hair, strangely shaped clothes, tattered tweed tops, crumpled corduroy pants, and a big grin. Absent-minded. It often goes that the more bizarre and eccentric this person is, the more likely he is to become a good decipherer.
The entire code-breaking process is under the control of the British Secret Intelligence Service (MI-6). They managed the Bletchley Estate very strictly, and all those who entered the "Bush Village" were carefully scrutinized and told that they would never be allowed to go out unless they were allowed to do so after the war. And the entire work content of "Cloth Village" and the production process of the product are listed as "Eltera" - super secret.
Menzies, the director of the British Secret Intelligence Service, deeply understood the importance of "Eltra", and he believed that the first task was to take a series of measures to ensure its security, and if the slightest negligence was leaked, everything would be abandoned.
First of all, we must eliminate the danger of "production" and "creation" and "Eltra" personnel falling into the hands of the enemy, so as not to betray secrets under the threat and inducement of the enemy. As a result, the staff who entered the Bletchley Estate were told: once in, they could never get out.
Second, "Eltra" is disguised as intelligence obtained from other sources, the true source of which is known only to a very small number of people. In addition, its dissemination and use are severely restricted. To this end, the Intelligence Service established a new secret agency, the Special Liaison Group, to administer "Ertra". The head of the Special Liaison Group is Lieutenant Colonel WinterBotham, former Chief of the Air Force Division of the Secret Intelligence Service. The analysis and synthesis of intelligence data was sent to Churchill every day, and he relied on such reports to guide the war and read Hitler's telegrams as quickly as possible. In addition, the distribution of "Ertra" is limited to the Director of Secret Intelligence, the Director of Naval Intelligence, the Director of Air Intelligence and the Chief of Intelligence of the Air Force Staff. It is never issued directly to units below the command of the army group, except after it is disguised in the form of a combat order.
Third, it was stipulated that all "Ertras" concerning the activities of German ships and tanks could not act alone on the basis of the system in order to prevent the enemy's suspicious code from being deciphered. At the same time, before carrying out operations against the Germans, aerial reconnaissance must be carried out in advance that can be seen by the Germans.
All kinds of thoughtful and meticulous secrecy work has indeed ensured the safety of "Ertra". It wasn't until 30 years after the war that a book by Winterbotham broke the silence of a generation and revealed the most tightly guarded secret of World War II. It can be said that the success of british intelligence agencies in defending "Eltra" is second only to the breakthrough of "Enigma".
On 2 July 1940, Hitler issued an order to invade Britain, and a battle plan code-named "Sea Lion" was put into effect, the purpose of which was to prevent Britain from being used as a base for continuing the war against Germany. The Battle of Britain has begun! The critical juncture that will determine the life and death of the people of the British Isles has arrived. As Churchill said, "Everything depends on winning this war..."
The German Air Force carried out massive airstrikes in a vain attempt to wipe out the RAF. Control of British airspace cleared the way for a massive invasion by the German Army. At this time, "Ertra" sent Churchill and the Air Force Staff most, sometimes even all, of the plans, objectives and tactics of the Luftwaffe in time, so that the RAF could concentrate its forces, choose the appropriate fighters, and take the initiative to deal with the enemy's attack.
The uphill battle continued, and the Anglo-German air forces were still engaged in a deadly battle. Goering declared 15 September "Eagle Day", the day on which the Luftwaffe would launch a powerful and final frenzied attack aimed at destroying the RAF. Hitler decided that eagle days would invade if they succeeded, and stop if they failed. Britain obtained this decisive information through "Eltra". After analysing the Germans' intentions, the RAF made a combat deployment, with squadrons entering the best position to intercept the Luftwaffe. Defensive facilities such as radar and anti-aircraft guns are on emergency alert.
The battle of Eagle Day was particularly brutal and fierce, and the skies over southeast England were burned red by the flames of war. The Luftwaffe attacked London with 1,000 bombers and 700 fighters, while the British relied on only the remnants of the squadrons after the battle for days to resist. The British understood that they had no room for maneuver, only to resist desperately. It was not until around 5 p.m. that the German aircraft finally retreated in disappointment, and the RAF still controlled British airspace.
Two days later, "Ertra" received a message from Hitler ordering the dismantling of paratroopers on Dutch airfields. Churchill laughed happily at the news, which meant that Hitler had abandoned his plans for an invasion, at least not this year. He lit a big cigar and said, "It's time for us to get some fresh air." ”
"Eltra" helped thwart the German invasion and saved countless British lives. Soon, however, the British defended what Churchill called "my most secret source", "Ertra", at the expense of Coventry.
On 12 November 1940, intercepted information indicated that the Luftwaffe would carry out a massive and heavy bombardment of Coventry Cathedral and the industrial area on 14 and 15 November. This is the Moonlight Sonatas action plan.
The motivation for action is revenge. On 8 November 1940, when Hitler was speaking in Munich to commemorate the 17th anniversary of the Beer Hall Riots, the RAF carried out air raids, and although Hitler had left the Löwenbauern Beer Hall before the bombing, the Beer Hall was bombed and some people were killed and injured. Hitler frantically shouted "Special revenge on Britain!" ”
It was clear that the Germans were going to punish Coventry the same way they had punished Rotterdam on 14 May 1940. On that occasion, they razed the ancient city to the ground and killed more than 900 people. The Germans used only 57 Heinkel bombs when they attacked Rotterdam. And "Eltra" indicated that they planned to drop 509 Heinkels in Coventry, which would undoubtedly cause more damage.
Coventry is located in the heart of England's interior, about 100 kilometres from London, with a population of about 250,000. It is an important industrial city, with important factories such as aircraft, automobiles, machine tools, precision instruments, communication equipment, etc., and is one of the main arsenals in Britain.
Intelligence indicates that in addition to Coventry, two major cities– Birmingham (code-named "Umbrella" Action Plan) and Wolverhampton (code-named "Whole" Action Plan), will also be attacked during the Moonlight in November. Intelligence revealed in detail the tactics and scale of the Germans' air raids.
"Eltra" won at least 48 hours for the British. The British High Command urgently studied and formulated measures to defend Coventry, and if the defenses were strengthened, the Germans understood that the air raid information had been leaked, and then suspected their own cryptography. No, there is no risk of the enemy being suspicious and replacing the updated Enigma, which will lose "Eltra" at least for a long time. After repeatedly weighing and weighing the pros and cons, the British decided not to strengthen the air defenses of Coventry and Birmingham.
It was a tragic decision, despite Britain's ability to protect Coventry. But they had to do it for the sake of long-term gain, for the sake of ultimate victory.
The day of the air raids is coming. On this day, the moonlight is bright, and Coventry is bathed in bright moonlight. Suddenly, air raid sirens rang out across the night sky. Unprepared people panicked to find that swarms of Heinkel planes were roaring overhead, and the first incendiary bombs dropped by the first aircraft caused a skyrocketing fire, and subsequent groups of aircraft alternately dropped incendiary and high-explosive bombs marked by them. The 10-hour-long attack caused the Coventry people's proud St. Michael's Cathedral (built in the 14th century) to collapse. The city was reduced to rubble, and some areas were razed to the ground like Rotterdam. Among the citizens, about 554 people died and 4860 people suffered injuries of varying degrees.
What the Germans called "the largest attack in the history of air warfare" was over, and the Moonlight Sonata program completed its mission.
Britain took effective steps to prevent Birmingham and Wolverhampton from repeating the mistakes of the past. The former greatly reduced losses, while the latter could even be said to have completely thwarted the air raids, as the Germans saw the sudden strengthening of air defences, which they thought might be the result of an attack on Coventry.
A few weeks after the Coventry massacre, "Eltra" once again proved to people that it was worth taking risks, even bloody sacrifices to protect. It revealed a strategically important secret: Hitler abandoned his plan to invade Britain and was moving his most elite troops, tanks and air force from France to the Balkans or Poland.
A growing body of intelligence indicated that Hitler was preparing to invade the Soviet Union. Churchill worriedly told Roosevelt, who had recently been re-elected president of the United States: "We are entering a dim stage. It is clear that it must be a protracted and widening war". In order to jointly fight against German fascism, Churchill issued a warning to Moscow through normal diplomatic channels.
The contribution of "Eltra" does not stop there, it has continued to create miracles during the long years of war.
- Because the "bomb" deciphered the Enigma code of the Luftwaffe and the Italian fleet, it won the first British naval battle in World War II, the Battle of Matapan Point, and destroyed the Italian fleet. Defended the British Navy's sea control over the eastern Mediterranean.
On 20 May 1941, the large German warship Bismarck, accompanied by the new cruiser Prinz Eugen, sailed from the Baltic Sea into Norwegian territorial waters. After receiving the "Eltra" report, the Admiralty waited for the opportunity to sink the "Bismarck" in one fell swoop. When the news reached Britain, people rejoiced at this great victory.
In the African theater, relying on the intelligence of "Eltra", the British dealt a fierce blow to the convoys of transport ships that supplied Marshal Rommel with fuel and ammunition. Not only did they know the exact route of the convoy, but they even knew which ship was carrying important supplies. In this way, about half of the ships were sunk. Rommel's logistical supplies were extremely scarce and he was in a slump. The steady stream of "Eltra" gave Bernard Montgomery, commander of the British Eighth Army in Africa, a thorough knowledge of the enemy's situation, and even knew that Rommel was suffering from jaundice. When he confidently launched an attack on El Alamein, the Desert Fox had to pick up its tail and evacuate Africa.
- During the Battle of Italy. Eltra provided General Harold Alexander, who was far away in Naples, with information on the layout and organization of enemy forces in thousands of areas, the strength of the German army, the movement of increased troops and reserves, and the number of weapons and equipment, ranging from officer transfers, reinforcements, and casualties.
In May 1941, Bletchley Manor was pleasantly surprised to receive an unexpected gift, in which the Royal Navy destroyed a German U-110 submarine and, before its explosion, took out Enigma and the secret copy and the secret table documents. Without the enemy being aware, the British had the key to unlocking the German chains of blockade of the Atlantic. The Royal Navy relied on accurate intelligence to pursue enemy submarines, which greatly reduced Allied shipping losses. In later days, although the German Navy constantly changed keys and even switched to new models of Enigma, their lead was always temporary.
The "Eltra" also played an important role in the Allied "Torch Plan", which continuously provided a large amount of high-level intelligence and confirmed that the "Torch Plan" had hooked the Germans. Its accuracy and reliability won the favor of General Eisenhower.
In this way, during the brutal war, the British successfully defended the top-secret weapon that made them proud, the "Eltra". And "Ertra" also faithfully kept its promise and brought great victories to the Allies.
In 1943, dozens of U.S. officers were allowed to enter the Bletchley Estates, not to visit, and most of them would serve as advisers to the U.S. Army Command "Eltra", a few of whom worked until the end of the war.
The Bletchley Estate and its "Eltra" played an inestimable role in the Allied eventual victory in the war. As The Allied Supreme Commander, General Eisenhower, wrote in a letter to Sir Menzies, Chief of Secret Intelligence, in July 1945, before the end of the War:
"I had hoped to visit Bletchley Manor... Thank you for your great help to the Allies. I know very well that the materials you have provided to us must be obtained through a great deal of labor and arduous struggle. I also know very well that you must have encountered many setbacks and difficulties, and that you have always won with your excellent efforts. The information you sent there before and during this last campaign was of inestimable value to me. ...... On my behalf, therefore, please express my heartfelt admiration and sincere thanks to everyone who has done this work for their decisive contribution to the fighting of the Allied forces. ”
The thousands of men and women working at "Bletchley Manor" could not receive the same public praise as the heroes of the battle, who for a long time would need to remain silent along with Bletchley Manor and its record, and bury the joy of victory in their hearts. But history will not forget them.
Churchill once affectionately and proudly praised the workers of Bletchley Manor as "geese that lay golden eggs— never clucking." And "Eltra", people still argue about it today, judging it, because it has always been an incomparable miracle in this war.