Completed in 1923 she made training cruises to the Black and Mediterranean Seas, South America and numerous shorter visits to ports in northern Europe.

Niels Juel was extensively modernized in the mid-1930s and remained operational after Nazi Germany occupied Denmark in 1940.

She was deliberately run aground by her crew to deny the ship to the Germans, but Niels Juel was not badly damaged.

Niels Juel was originally intended to be an improved version of Peder Skram, a Herluf Trolle-class coastal defence ship.

[1] Reports from battles between the British and the Germans caused the Danes to change her secondary armament to 120-millimeter (4.7 in) guns in 1917, but work stopped completely when the war ended on 11 November 1918.

During her sea trials, they produced 6,061 ihp (4,520 kW) and Niels Juel reached a maximum speed of 16.1 knots (29.8 km/h; 18.5 mph).

[5] The Navy had difficulties procuring the 15-centimeter guns that it wanted for the ship's main battery, rejecting proposals from French, British and Swedish manufacturers as unsatisfactory.

[6] The mounts had a range of elevation from -10° to +30° and the guns fired 46-kilogram (101 lb) projectiles at a muzzle velocity of 835 m/s (2,740 ft/s)[7] at a rate of five to seven rounds per minute.

[9] The ship was provided with a pair of 3-meter (9 ft 10 in) Zeiss stereoscopic rangefinders, one on the roof of the conning tower and the other on a platform abaft the mainmast.

In April 1937, her anti-aircraft armament was augmented with fourteen 8-millimeter (0.3 in) Madsen R.K. L/75 M/37 machine guns in twin mounts.

[13] On 21 October Niels Juel made her first training cruise, visiting Dartmouth, United Kingdom, Cadiz, Spain, Madeira, Portugal, and the Cape Verde Islands, en route to South America.

The following year the ship made a cruise to the Faeroe Islands and Iceland with the royal family aboard.

Niels Juel served as the royal yacht for a state visit to Finland in 1928, during which she was escorted by the cruiser Heimdal.

[14] The ship made a training cruise to the Mediterranean in 1929, where she visited ports in France, Spain, Italy and Libya as well as Lisbon, Portugal.

Her crew was filled out as the Navy mobilized and Niels Juel joined the rest of the fleet near Aarhus.

Her crew was recalled on 8 April, but Niels Juel was not ready for war when the Germans invaded the following day.

Niels Juel was in Holbæk when her captain, Commander Carl Westermann, was ordered take his ship to be interned in Sweden.

None of the bombs hit Niels Juel, but shock damage from near misses knocked out electrical power and deformed some of the hull plating and bulkheads.

Realising there was little hope of reaching Sweden, Westermann decided to run the ship aground near Nykøbing Sjælland.

She was disarmed, renamed Nordland, and commissioned into the Kriegsmarine in September 1944 after which she became a stationary training ship at Stolpmünde (modern Ustka, Poland).