HNoMS "Gyller was a commissioned into the Royal Norwegian Navy in 1938. Along with the other "Sleipner"-class vessels in commission at that time, she took part in protecting Norwegian neutrality during the Second World War. After initially serving in the far north during the Finno-Soviet Winter War, she was redeployed to Southern Norway, escorting ships through Norwegian territorial waters. When the Germans invaded Norway on 9 April 1940, she was docked at Kristiansand. After taking part in the defence of the port city, she was captured intact by the invading Germans. Renamed Löwe", she sailed with Nazi Germany's "Kriegsmarine" for the duration of the war.