The 1st U-boat flotilla (German "1.
 Unterseebootsflottille") also known as the Weddigen flotilla, was the first operational U-boat unit in Nazi Germany's "Kriegsmarine" (navy).
 Founded on 27 September 1935 under the command of "Fregattenkapitän" Karl Dönitz, it was named in honor of "Kapitänleutnant" Otto Weddigen.
 Weddigen, a U-boat commander during World War I, died on 18 March 1915 after his submarine "U-29" was rammed by the British battleship HMS "Dreadnought" in the North Sea.
Karl Dönitz (sometimes spelt Doenitz) (] ; 16 September 1891 – 24 December 1980) was a German admiral who played a major role in the naval history of World War II.
 Dönitz briefly succeeded Adolf Hitler as the head of state of Germany.
The Discriminant Book (German: Kenngruppenbuch; literally: "Groups to identify the key to the receiver") shortened to K-Book ("K. Buch"), and also known as the "indicator group book" or "identification group book" was a secret distribution list in booklet form, which listed trigraphs in random order.
 The Kenngruppenbuch was introduced in May 1937, and used by the Kriegsmarine (German War Navy) during World War II as part of the Naval Enigma message encipherment procedure, to ensure secret and confidential communication between Karl Dönitz, Commander of Submarines (BdU) in the Atlantic and in the Mediterranean operating German submarines.
 The Kenngruppenbuch was used in the generation of the Enigma message Key that was transmitted within the message Indicator.
 The Kenngruppenbuch was used from the 5th October 1941, for the Enigma Model M3, and from 1st February 1942 exclusively for the Enigma M4.
 It must not be confused with the Kenngruppenheft which was used with the Short Signal Book (German: "Kurzsignalbuch").
The Flensburg Government (German: "Flensburger Regierung" ), also known as the Flensburg Cabinet ("Flensburger Kabinett"), the Dönitz Government ("Regierung Dönitz"), or the Schwerin von Krosigk Cabinet ("Kabinett Schwerin von Krosigk"), was the short-lived government of Nazi Germany during a period of three weeks around the end of World War II in Europe.
 The government was formed following the suicide of Adolf Hitler on 30 April 1945 during the Battle of Berlin.
 It was headed by Grand Admiral Karl Dönitz as the Reichspräsident and Lutz Graf Schwerin von Krosigk as the Leading Minister.
Fritz-Julius Lemp (19 February 1913 – 9 May 1941) was a captain the Kriegsmarine during World War II and commander of "U-28" , "U-30" and "U-110" .
 He sunk the British passenger liner "SS Athenia" in September 1939, in violation of the Hague conventions.
 The German responsibility for the sinking was suppressed by Admiral Karl Dönitz and the Nazi propaganda.
 Lemp died on 9 May 1941 when the U-boat he commanded was captured.
The post of Führer der Unterseeboote (FdU) ("Type Commander, Submarines") was the senior commanding officer of the submarine service in the Kaiserliche Marine of World War I and the Kriegsmarine of World War II, and the title of several senior commands during the war.
 From January 1936 and until 17 October 1939, Karl Dönitz served in this position.
 Thereupon Dönitz was named "Befehlshaber der Unterseeboote (BdU)" ("Commander of the U-boats"), and two subordinate FdU posts were established, "FdU West" ("FdU West") and "FdU Ost" ("FdU East").
Klaus Dönitz (13 May 1920 - 13 May 1944) was a German naval officer.
 He was the elder of the two sons of Admiral Karl Dönitz.
A type commander in the Kriegsmarine was a permanently assigned administrative officer in the organization of the Kriegsmarine which oversaw the development, deployment, and in some cases operational activities of the various classes of German naval vessels. Due to cross jurisdiction with the Navy group commanders, who tactically commanded all vessels at sea, some type commanders were little more than ceremonial officers who held a title with little authority.
 Others, such as Karl Dönitz who commanded the German U-boat force, exercised near total independence and held enormous authority, both operationally and administrative.
SM "UB-68" was a German Type UB III submarine or U-boat in the German Imperial Navy (German: "Kaiserliche Marine" ) during World War I.
 The U-boat was ordered on 20 May 1916.
 She was commissioned into the German Imperial Navy on 5 October 1917 as SM "UB-68".
 The submarine conducted five patrols and sank five ships during the war.
 Under the command of Karl Dönitz, on 4 October 1918 "UB-68" encountered technical problems and had to surface where she was sunk by gunfire at .
 There was one dead and thirty-three survivors.
 Other sources name the British warships involved in the sinking of "UB-68" as HMS "Snapdragon" and  , and claim four crew members died in the event.
A tonnage war is a military strategy aimed at merchant shipping.
 The premise is that the enemy has only a finite number of ships, and a finite capacity to build replacements for them.
 The concept was made famous by U-boat commander Karl Dönitz, who wrote: "The shipping of the enemy powers is one great whole.
 It is therefore in this connection immaterial where a ship is sunk—it must still in the final analysis be replaced by a new ship".

Question: What country of origin does Type commander and Karl Dönitz have in common?
Answer: German