Named for Gebhard Leberecht von Blücher, the Prussian victor of the Battle of Waterloo, the ship was laid down in August 1935 and launched in June 1937.

After completing a series of sea trials and training exercises, the ship was pronounced ready for service with the fleet on 5 April 1940.

She was armed with a main battery of eight 203 mm (8 in) guns and, although nominally under the 10,000-long-ton (10,160 t) limit set by the Anglo-German Naval Agreement, actually displaced over 16,000 long tons (16,260 t).

Immediately upon entering service, Blücher was assigned to the task force that supported the invasion of Norway in April 1940.

The ship led the flotilla of warships into the Oslofjord on the night of 8 April, to seize Oslo, the capital of Norway.

Several artifacts have been raised from the wreck, including one of her Arado 196 floatplanes, which was recovered during an operation to pump out leaking fuel oil from the ship in 1994.

The Admiral Hipper class of heavy cruisers was ordered in the context of German naval rearmament after the Nazi Party came to power in 1933 and repudiated the disarmament clauses of the Treaty of Versailles.

[5] Blucher never had more than two seaplanes on board, and en route to Oslo one had to rest on the catapult as one of the hangars was used for storing bombs and torpedoes.

[4] The ship was launched on 8 June 1937, and was completed slightly over two years later, on 20 September 1939, the day she was commissioned into the German fleet.

[11] As built, the ship had a straight stem, though after her launch this was replaced with a clipper bow increasing the overall length to 205.90 meters (675.5 ft).

In January 1940, she resumed her exercises in the Baltic, but by the middle of the month, severe ice forced the ship to remain in port.

[16] At 23:30 (Norwegian time) the south battery on Rauøy spotted the flotilla in the searchlight and fired two warning shots.

[17] Five minutes later, the guns at the Rauøy battery fired four rounds at the approaching Germans, but visibility was poor and no hits were scored.

[21] Despite the apparent loss of surprise, the Blücher proceeded further into the fjord to continue with the timetable to reach Oslo by dawn.

At 04:20, Norwegian searchlights again illuminated the ship and at 04:21 the 28 cm (11 in) guns of Oscarsborg Fortress opened fire on Blücher at very close range, beginning the Battle of Drøbak Sound with two hits on her port side.

The main range finder in the top of the battle mast was knocked out of alignment, but Blücher had four more major rangefinders.

The Kopås battery ceased firing at Blücher and engaged the next target, Lützow, scoring multiple hits.

[24] First engineer Karl Thannemann wrote in his report that the hits from the guns on Drøbak, which were fired on the starboard side, were all between section IV and X in a length of 75 m (246 ft) amidships, between B-turret and C-turret.

The 15 cm guns in the Kopås battery were all standing in open positions with a wide sector of firing, and they were still within range.

[29] Naval historian Erich Gröner states that the number of casualties is unknown,[10] and Henrik Lunde gives a loss of life figure ranging between 600 and 1,000 soldiers and sailors.

The ground troops were landed on the eastern side of the fjord; they proceeded inland and captured Oscarborg Fortress by 09:00 on 10 April.

Airborne troops captured Fornebu Airport and completed the encirclement of the city, and by 14:00 on 10 April it was in German hands.

The delay caused by the temporary withdrawal of Blücher's task force, however, allowed the Norwegian government and royal family to escape the city.