At the Battle of Dogger Bank on 24 January 1915, Blücher was slowed significantly after being hit by gunfire from the British battlecruiser squadron under the command of Vice Admiral David Beatty.

Rear Admiral Franz von Hipper, the commander of the German squadron, decided to abandon Blücher to the pursuing enemy ships in order to save his more valuable battlecruisers.

[6] One week after the final decision was made to authorize construction of Blücher, the German naval attache obtained the actual details of the new British ships, called the Invincible class.

[7] Blücher was therefore arguably obsolete even before her construction started, and was rapidly surpassed by the German Navy's battlecruisers, the first of which (Von der Tann) was ordered in 1907.

[9] Documents from the German naval archives generally indicate satisfaction with Blücher's minor pitch and gentle motion at sea.

[11][12] The ship had a secondary battery of eight 15 cm (5.9 in) quick-firing guns mounted in MPL C/06 casemates,[13][14] four centered amidships on either side of the vessel.

The armored belt was supplemented by a 3.5 cm (1.4 in) torpedo bulkhead,[9] though this only ran between the forward and rear centerline gun turrets.

[17] On 2 November 1914, Blücher—along with the battlecruisers Moltke, Von der Tann, and Seydlitz, and accompanied by four light cruisers, left the Jade Bight and steamed towards the English coast.

[18] The flotilla arrived off Great Yarmouth at daybreak the following morning and bombarded the port, while the light cruiser Stralsund laid a minefield.

On the way, a heavy fog covered the Heligoland Bight, so the ships were ordered to halt until visibility improved and they could safely navigate the defensive minefields.

[18] At 03:20, CET on 15 December 1914, Blücher, Moltke, Von der Tann, the new battlecruiser Derfflinger, and Seydlitz, along with the light cruisers Kolberg, Strassburg, Stralsund, Graudenz, and two squadrons of torpedo boats left the Jade estuary.

Room 40 began decrypting German signals, and on 14 December, intercepted messages relating to the plan to bombard Scarborough.

[19] The exact details of the plan were unknown, and it was assumed that the High Seas Fleet would remain safely in port, as in the previous bombardment.

Beatty presumed that the German cruisers were the advance screen for Hipper's ships, but the battlecruisers were some 50 km (27 nmi; 31 mi) ahead.

The captain of Moltke was furious; he stated that Ingenohl had turned back "because he was afraid of eleven British destroyers which could have been eliminated ...

"[24] In early January 1915 the German naval command found out that British ships were conducting reconnaissance in the Dogger Bank area.

Admiral Ingenohl was initially reluctant to attempt to destroy these forces, because the I Scouting Group was temporarily weakened while Von der Tann was in drydock for periodic maintenance.

Konteradmiral (counter admiral) Richard Eckermann—the Chief of Staff of the High Seas Fleet—insisted on the operation, and so Ingenohl relented and ordered Hipper to take his battlecruisers to the Dogger Bank.

[25] On 23 January, Hipper sortied, with Seydlitz in the lead, followed by Moltke, Derfflinger, and Blücher, along with the light cruisers Graudenz, Rostock, Stralsund, and Kolberg and 19 torpedo boats from V Flotilla and II and XVIII Half-Flotillas.

Although they were unaware of the exact plans, the cryptographers of Room 40 were able to deduce that Hipper would be conducting an operation in the Dogger Bank area.

Hipper immediately turned his battlecruisers towards the gunfire, when, almost simultaneously, Stralsund spotted a large amount of smoke to the northwest of her position.

[26] Hipper later remarked: The presence of such a large force indicated the proximity of further sections of the British Fleet, especially as wireless intercepts revealed the approach of 2nd Battlecruiser Squadron ...

They were also reported by Blücher at the rear of the German line, which had opened fire on a light cruiser and several destroyers coming up from astern ...

The battlecruisers under my command found themselves, in view of the prevailing [East-North-East] wind, in the windward position and so in an unfavourable situation from the outset ...[26] Hipper turned south to flee, but was limited to 23 kn (43 km/h; 26 mph), which was Blücher's maximum speed at the time.

However, the three leading German battlecruisers, Seydlitz, Derfflinger, and Moltke, had concentrated their fire on Lion and scored several hits; two of her three dynamos were disabled and the port side engine room had been flooded.

[29] At 11:48, Indomitable arrived on the scene, and was directed by Beatty to destroy the battered Blücher, which was already on fire and listing heavily to port.

Beatty, in the stricken Lion, ordered the remaining battlecruisers to "Engage the enemy's rear", but signal confusion caused the ships to target Blücher alone.

[34] Admiral Hipper had originally intended to use his three battlecruisers to turn about and flank the British ships, in order to relieve the battered Blücher, but when he learned of the severe damage to his flagship, he decided to abandon the armored cruiser.

But as I was informed that in my flagship turrets C and D were out of action, we were full of water aft, and that she had only 200 rounds of heavy shell left, I dismissed any further thought of supporting the Blücher.

[31] Kaiser Wilhelm II was enraged by the destruction of Blücher and the near sinking of Seydlitz, and ordered the High Seas Fleet to remain in harbor.