Jan Lesniak
Encyclopedia
Jan Leśniak was a Polish
military intelligence
officer in the Interbellum and World War II
.
Office and for a year, from April 1938, its director.
Leśniak in 1976 told historian Richard Woytak
that, beginning in fall 1935, he received intelligence whose source he had not been informed of and which in fact came from decryption of German Enigma
messages by the Polish General Staff's Cipher Bureau
.
Like British and American officers who would during World War II
receive Ultra
intelligence gleaned from Enigma decrypts, then-Major Leśniak began questioning its reliability. "Some of the information was so important, about [German] mobilizations and so on, that... I questioned [it] in '36 [and was told its source] shortly afterwards." Leśniak was apparently initiated into the secret by Colonel Stefan Mayer
, the General Staff's intelligence chief. Henceforth Leśniak was in direct contact with Col. Gwido Langer
and Major Maksymilian Ciężki
of the Cipher Bureau
and with Captain Wiktor Michałowski of the Bureau's German section.
Often, when the Cipher Bureau was missing information or had decrypted half a military unit's or individual's name, Leśniak was able to supply the lacking information.
Leśniak recalled that the decrypts included messages between the German Ministry of War in Berlin and Wehrkreises in Königsberg (Wehrkreis no. 1) and elsewhere, concerning postings, military build-ups and preparations for mobilization. There was less information on the air force, but a great deal on the navy, e.g. movements of naval ships putting out from Kiel
and into the Baltic Sea
.
The Enigma decrypts helped Polish intelligence build up before the outbreak of World War II
a remarkably (95%) complete picture of the German military order of battle
and of her mobilization
preparations.
Enigma decrypts came into Leśniak's office in varying volume: sometimes several, sometimes a dozen or more, a week. The greatest flow was in 1938. In 1939 there were few decrypts. When Leśniak made inquiries, he learned that the Cipher Bureau
was having difficulties with decryption, except for Gestapo
and Sicherheitsdienst
and some air force messages.
In mid-April 1939, Leśniak turned the German Office over to Lt. Col. Stanisław Bień and formed a Situation Office for wartime service, which he headed to and through the German invasion of Poland in September 1939. Later he would head a German Office at the Polish General Staff in France and in London.
During the 1939 invasion of Poland, according to Leśniak, there was no Enigma intelligence: "When there is no radio monitoring, there are no messages, and you can't work. It was only in France [in late 1939] that this source started up again, after the whole [Cipher Bureau] team... had been turned over to the French [general] staff."
Lt. Col. Leśniak in 1944-1945 served as deputy chief of the Polish General Staff's Section II (intelligence) in Great Britain.
He died after being struck by a motor vehicle while visiting Vienna in 1976.
Poland
Poland , officially the Republic of Poland , is a country in Central Europe bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian exclave, to the north...
military intelligence
Military intelligence
Military intelligence is a military discipline that exploits a number of information collection and analysis approaches to provide guidance and direction to commanders in support of their decisions....
officer in the Interbellum and World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
.
Career
Leśniak was from fall 1935 deputy director of the Polish General Staff's GermanGermany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
Office and for a year, from April 1938, its director.
Leśniak in 1976 told historian Richard Woytak
Richard Woytak
Richard Andrew Woytak was an American historian who specialized in European history of the Interbellum and World War II...
that, beginning in fall 1935, he received intelligence whose source he had not been informed of and which in fact came from decryption of German Enigma
Enigma machine
An Enigma machine is any of a family of related electro-mechanical rotor cipher machines used for the encryption and decryption of secret messages. Enigma was invented by German engineer Arthur Scherbius at the end of World War I...
messages by the Polish General Staff's Cipher Bureau
Biuro Szyfrów
The Biuro Szyfrów was the interwar Polish General Staff's agency charged with both cryptography and cryptology ....
.
Like British and American officers who would during World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
receive Ultra
Ultra
Ultra was the designation adopted by British military intelligence in June 1941 for wartime signals intelligence obtained by "breaking" high-level encrypted enemy radio and teleprinter communications at the Government Code and Cypher School at Bletchley Park. "Ultra" eventually became the standard...
intelligence gleaned from Enigma decrypts, then-Major Leśniak began questioning its reliability. "Some of the information was so important, about [German] mobilizations and so on, that... I questioned [it] in '36 [and was told its source] shortly afterwards." Leśniak was apparently initiated into the secret by Colonel Stefan Mayer
Stefan Mayer
Colonel Stefan A. Mayer was a Polish military intelligence officer and prewar chief of the Intelligence Department within the Polish General Staff's Section II...
, the General Staff's intelligence chief. Henceforth Leśniak was in direct contact with Col. Gwido Langer
Gwido Langer
Lt. Col. Karol Gwido Langer was chief of the Polish General Staff's Cipher Bureau from at least mid-1931.-Life:...
and Major Maksymilian Ciężki
Maksymilian Ciezki
Maksymilian Ciężki was the head of the German section of the Polish Cipher Bureau in the 1930s, during which time the Bureau decrypted German Enigma messages....
of the Cipher Bureau
Biuro Szyfrów
The Biuro Szyfrów was the interwar Polish General Staff's agency charged with both cryptography and cryptology ....
and with Captain Wiktor Michałowski of the Bureau's German section.
Often, when the Cipher Bureau was missing information or had decrypted half a military unit's or individual's name, Leśniak was able to supply the lacking information.
Leśniak recalled that the decrypts included messages between the German Ministry of War in Berlin and Wehrkreises in Königsberg (Wehrkreis no. 1) and elsewhere, concerning postings, military build-ups and preparations for mobilization. There was less information on the air force, but a great deal on the navy, e.g. movements of naval ships putting out from Kiel
Kiel
Kiel is the capital and most populous city in the northern German state of Schleswig-Holstein, with a population of 238,049 .Kiel is approximately north of Hamburg. Due to its geographic location in the north of Germany, the southeast of the Jutland peninsula, and the southwestern shore of the...
and into the Baltic Sea
Baltic Sea
The Baltic Sea is a brackish mediterranean sea located in Northern Europe, from 53°N to 66°N latitude and from 20°E to 26°E longitude. It is bounded by the Scandinavian Peninsula, the mainland of Europe, and the Danish islands. It drains into the Kattegat by way of the Øresund, the Great Belt and...
.
The Enigma decrypts helped Polish intelligence build up before the outbreak of World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
a remarkably (95%) complete picture of the German military order of battle
Order of battle
In modern use, the order of battle is the identification, command structure, strength, and disposition of personnel, equipment, and units of an armed force participating in field operations. Various abbreviations are in use, including OOB, O/B, or OB, while ORBAT remains the most common in the...
and of her mobilization
Mobilization
Mobilization is the act of assembling and making both troops and supplies ready for war. The word mobilization was first used, in a military context, in order to describe the preparation of the Prussian army during the 1850s and 1860s. Mobilization theories and techniques have continuously changed...
preparations.
Enigma decrypts came into Leśniak's office in varying volume: sometimes several, sometimes a dozen or more, a week. The greatest flow was in 1938. In 1939 there were few decrypts. When Leśniak made inquiries, he learned that the Cipher Bureau
Biuro Szyfrów
The Biuro Szyfrów was the interwar Polish General Staff's agency charged with both cryptography and cryptology ....
was having difficulties with decryption, except for Gestapo
Gestapo
The Gestapo was the official secret police of Nazi Germany. Beginning on 20 April 1934, it was under the administration of the SS leader Heinrich Himmler in his position as Chief of German Police...
and Sicherheitsdienst
Sicherheitsdienst
Sicherheitsdienst , full title Sicherheitsdienst des Reichsführers-SS, or SD, was the intelligence agency of the SS and the Nazi Party in Nazi Germany. The organization was the first Nazi Party intelligence organization to be established and was often considered a "sister organization" with the...
and some air force messages.
In mid-April 1939, Leśniak turned the German Office over to Lt. Col. Stanisław Bień and formed a Situation Office for wartime service, which he headed to and through the German invasion of Poland in September 1939. Later he would head a German Office at the Polish General Staff in France and in London.
During the 1939 invasion of Poland, according to Leśniak, there was no Enigma intelligence: "When there is no radio monitoring, there are no messages, and you can't work. It was only in France [in late 1939] that this source started up again, after the whole [Cipher Bureau] team... had been turned over to the French [general] staff."
Lt. Col. Leśniak in 1944-1945 served as deputy chief of the Polish General Staff's Section II (intelligence) in Great Britain.
He died after being struck by a motor vehicle while visiting Vienna in 1976.
See also
- History of Polish Intelligence ServicesHistory of Polish Intelligence ServicesThis article covers the history of Polish intelligence services dating back to the Polish-Lithuanian Commonwealth.-Commonwealth:Though the first official Polish government service entrusted with espionage, intelligence and counter-intelligence was not formed until 1918, Poland and later the...
. - List of Poles