"Forsvarets Spesialkommando" can trace its roots back to the Second World War, when Norwegians served in the Norwegian Independent Company 1 (NOR.I.C.1) of the British Special Operations Executive including the famous Operation Gunnerside raid of the heavy water plant at Rjukan. On 25 March 1962, the Army Parachute Ranger School () was created. The focus of this school initially was to provide parachute training for certain groups of personnel within the Norwegian Armed Forces, and eventually the Paratrooper Platoon () was established in 1965. Specially selected personnel from this platoon were assigned to Ranger Command 1 in the old mobilization army of the Cold War and were on standby in case of war. In 1971, the Army Parachute Ranger School changed its name to the Army Ranger School () (HJS) to emphasize the training of Army Rangers. The main focus over the next decade was long-range reconnaissance patrols (LRRP). Based on an increase in international terrorism and Norway's newly developed offshore oil services, the government decided in 1979 to establish a counter-terrorism capacity within the Norwegian Armed Forces. In 1982, a decision was finally made that this task be given to the Army Ranger School with "Forsvarets Spesialkommando" (FSK) established as part of the Army Ranger School. On 1 June 1984, the 38 man unit was operational following assistance from the British Special Air Service and Special Boat Service. From the mid-1990s there was an increasing focus on international operations. To show that the Army Ranger School now had an operative arm as well as the traditional training role, it changed its name to the Army Ranger Command () in 1997. The same year, HJK moved from Trandum to Rena, where the unit is based today. During the 2000s, HJK changed its name to FSK/HJK, to reflect the two units that make up the command (FSK being the operative wing and HJK being the training wing). In 2004, the unit commenced reporting directly to the Chief of the Army. In 2013, the FSK/HJK name was discontinued and the operative SOF-unit is simply known as FSK. FSK has gone from being a cadre and training-unit for paratroopers and the mobilization army, to being a professional unit with substantial experience, robustness, competency and capacity. The unit has been deployed internationally on several occasions and has received international recognition for its efforts.