Question: The Norwegian commander who became Chief of Defence after Nazi Germany 's assault on Norway was in office for how long ?

text: Chief of Defence (Norway)
List of Chiefs of Defence

The Chief of Defence (Forsvarssjefen) is the highest-ranking officer of the Norwegian Armed Forces, second only to the King of Norway. Even though he holds the same rank as the King of Norway, according to the Norwegian Constitution the King holds the highest command of the Army, Air Force, Navy and Home Guard. The Chief of Defence is the top advisor to the Government regarding military issues. He is responsible for carrying out the mission the King or Minister of Defence gives to the Military. He is also Norway's representative to NATO's military committee. The post was first established in 1940, and is currently held by Admiral Haakon Bruun-Hanssen.
No Chief of Defence Took office Left office Time in office Defence branch
1 Ruge , Otto Major General Otto Ruge ( 1882-1961 ) 18 May 1940 9 June 1940 22 days Army
- Fleischer , Carl Gustav Major General Carl Gustav Fleischer ( 1883-1942 ) Acting 10 June 1940 22 February 1942 1 year , 257 days Army
2 Hansteen , Wilhelm von Tangen Major General Wilhelm von Tangen Hansteen ( 1896-1980 ) 23 February 1942 30 June 1944 2 years , 128 days Army
3 Olav HRH Crown Prince Olav ( 1903-1991 ) 1 July 1944 15 July 1945 1 year , 14 days Army
( 1 ) Ruge , Otto Lieutenant General Otto Ruge ( 1882-1961 ) 16 July 1945 31 December 1945 168 days Army
- Corneliussen , Elias Rear Admiral Elias Corneliussen ( 1881-1951 ) Acting 1 January 1946 31 May 1946 150 days Navy
- Hansson , Halvor Major General Halvor Hansson ( 1886-1956 ) Acting 1 June 1946 31 July 1946 60 days Army
4 Berg , Ole Lieutenant General Ole Berg ( 1890-1968 ) ( as Chief of the Defence Staff ) 1 August 1946 31 October 1955 9 years , 91 days Army
5 Lambrechts , Finn Lieutenant General Finn Lambrechts ( 1900-1956 ) ( as Chief of the Defence Staff ) 1 November 1955 8 December 1956 † 1 year , 37 days Air Force
6 Øen , Bjarne Lieutenant General Bjarne Øen ( 1898-1994 ) ( as Chief of the Defence Staff ) 10 January 1957 31 December 1962 5 years , 355 days Air Force
( 6 ) Øen , Bjarne Lieutenant General Bjarne Øen ( 1898-1994 ) 1 January 1963 31 December 1963 364 days Air Force
7 Johannessen , Folke Hauger ( Vice ) Admiral Folke Hauger Johannessen ( 1913-1997 ) 1 January 1964 31 December 1972 8 years , 365 days Navy
8 Zeiner-Gundersen , Herman Fredrik General Herman Fredrik Zeiner-Gundersen ( 1915-2002 ) 1 February 1972 20 March 1977 5 years , 47 days Army
9 Hamre , Sverre B . General Sverre B. Hamre ( 1918-1990 ) 21 March 1977 30 June 1982 5 years , 70 days Army
10 Hauge , Sven General Sven Hauge ( 1923-1997 ) 1 July 1982 30 June 1984 1 year , 365 days Air Force
11 Bull-Hansen , Fredrik General Fredrik Bull-Hansen ( 1927-2018 ) 1 July 1984 31 August 1987 3 years , 61 days Army
12 Eide , Vigleik General Vigleik Eide ( 1933-2011 ) 31 August 1987 5 September 1989 2 years , 5 days Army
13 Rein , Torolf Admiral Torolf Rein ( born 1934 ) 5 September 1989 31 October 1994 5 years , 56 days Navy
14 Solli , Arne General Arne Solli ( 1938-2017 ) 31 October 1994 30 April 1999 4 years , 181 days Army
15 Frisvold , Sigurd General Sigurd Frisvold ( born 1947 ) 1 May 1999 31 March 2005 5 years , 334 days Army