Kurt Albert Jahnke was a German-American intelligence agent and saboteur active both during World War I

World War I

World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

 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...

.

Born in Gnesen

Gniezno

Gniezno is a city in central-western Poland, some 50 km east of Poznań, inhabited by about 70,000 people. One of the Piasts' chief cities, it was mentioned by 10th century A.D. sources as the capital of Piast Poland however the first capital of Piast realm was most likely Giecz built around...

, Jahnke immigrated to the United States in 1899, became a naturalized citizen, and served in the U.S. Marines in the Philippines

Philippines

The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...

. From August 1914, under the command of the German Counsel General Franz Bopp, Jahnke performed various intelligence and sabotage operations for the German Admiralty from his San Francisco base. He and his assistant Lothar Witzke

Lothar Witzke

Lothar Witzke was a German spy and saboteur active in the United States and Mexico during World War I.- Naval career :Born in Posen , Witzke was educated at Posen Academy then entered the German Naval Academy as a seventeen-year-old cadet. By the beginning of the war he was a lieutenant in the...

 were responsible for the March 1917 munitions explosion at the Mare Island Naval Shipyard

Mare Island Naval Shipyard

The Mare Island Naval Shipyard was the first United States Navy base established on the Pacific Ocean. It is located 25 miles northeast of San Francisco in Vallejo, California. The Napa River goes through the Mare Island Strait and separates the peninsula shipyard from the main portion of the...

 in San Francisco, "likely" responsible for the Black Tom explosion

Black Tom explosion

The Black Tom explosion on July 30, 1916 in Jersey City, New Jersey was an act of sabotage on American ammunition supplies by German agents to prevent the materiel from being used by the Allies in World War I.- Black Tom Island :...

 in Jersey City, New Jersey, and are suspected of other explosions and of fomenting labor strikes. When the United States entered the war in April 1917, Jahnke and Witzke moved their operations to Mexico City.

According to the Senate testimony of intelligence officer and double agent Dr. Paul Altendorf, who was undercover in Mexico City with the U.S. Military Intelligence Corps

Military Intelligence Corps (United States Army)

In the United States Armed Forces, Military Intelligence refers specifically to the intelligence components of the United States Army...

 from 1917 through April 1919, Jahnke had schemed a Mexican attack on the United States. An army of 45,000 men, funded by ambassador von Eckardt and trained by German reservists, would march against the U.S. in 1918 and "arose the Negroes to civil war.".

Back in Germany in the late 1930s Jahnke established the "Jahnke Büro", essentially a small private intelligence service reporting up to Rudolf Hess

Rudolf Hess

Rudolf Walter Richard Hess was a prominent Nazi politician who was Adolf Hitler's deputy in the Nazi Party during the 1930s and early 1940s...

. There is speculation that Jahnke was somehow involved in Hess's still-puzzling flight to Scotland in May 1941; true or not, he fell out of favor with Ribbentrop and the 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 his accumulated files were confiscated. Later in the war Jahnke served as intelligence advisor to Walter Schellenberg

Walter Schellenberg

Walther Friedrich Schellenberg was a German SS-Brigadeführer who rose through the ranks of the SS to become the head of foreign intelligence following the abolition of the Abwehr in 1944.-Biography:...

. He and his wife were captured by Russian SMERSH

SMERSH

SMERSH was the counter-intelligence agency in the Red Army formed in late 1942 or even earlier, but officially founded on April 14, 1943. The name SMERSH was coined by Joseph Stalin...

agents in April 1945, interrogated, and executed.