The armed forces museum (Forsvarsmuseet) free entrance:

was opened to the public in 1978 by King Olav V under the name of the Armed Forces Museum. The museum is located at Akershus Festning, in one of the old military arsenals from the 1860s. The main purpose of the museum is to show the Norwegian military history from the Viking Age to the 21st century.

Important themes include the union with Denmark until 1814, the union with Sweden until 1905, the German attack on Norway in 1940 and the sea battles during World War II

Max Manus: One of Norway`s greatest Second World War heroes. A ruthless anti-Nazi, specializing in sabotage, whose military skills were learned fighting with the Finns against the Soviet invaders in 1939 and 1940 and then honed with the Norwegian underground from the first days of the occupation until the liberation in May 1945. When the war ends, Max Manus drives through the flag-waving crowds as ceremonial bodyguard to the returning King Haakon VII.

Max Manus suffered from nightmares, alcoholism, and bouts of depression after his experiences in the war, some of which he talked about in interviews.  Max Manus wrote several books about his adventures and started a successful business

Max Manus died in 1996 aged 81.

Medals and honours according to Wikipedia:

• War Cross with two swords
• Defence Medal 1940–1945 (with rosette)
• Haakon VII 70th Anniversary Medal
• H. M. The King’s Commemorative Medal (1940–1945)
• Distinguished Service Order (United Kingdom)
• Military Cross with Bar (United Kingdom)
• Winter War commemorative with “Lappi” clasp
• Medal of Freedom with silver palm (United States)
• Medal of Norwegian volunteers to Finland (1940)