The Prinz Adalbert class was a group of two armored cruisers built for the German Kaiserliche Marine (Imperial Navy) under the terms of the Second Naval Law.

Prinz Adalbert spent her peacetime career as a gunnery training ship while Friedrich Carl initially served as the flagship of the fleet's reconnaissance forces.

Following the outbreak of World War I in July 1914, both vessels were mobilized; Friedrich Carl was assigned to the cruiser squadron in the Baltic Sea and was quickly sunk by Russian naval mines off Memel in November, though most of her crew was safely evacuated.

Prinz Adalbert initially served in the North Sea, supporting the Raid on Yarmouth in November 1914 before transferring to the Baltic to replace her lost sister.

Prinz Adalbert had little better luck, being torpedoed by British submarines twice in 1915, the first, in July, caused serious damage and necessitated lengthy repairs.

Six-hundred and seventy-two men were killed, the greatest single loss of life for the German Navy in the Baltic during the war; there were only three survivors of her sinking.

The First Naval Law in Germany, passed in 1898, envisioned a force of twelve armored cruisers intended for overseas service in the German colonies.

However, the German Navy required cruisers for operations with the fleet as well, and attempted to design ships that could fulfill both roles,[1] primarily due to budget constraints.

The first product of the 1898 Naval Law, Prinz Heinrich, was an alteration of an earlier vessel, Fürst Bismarck, equipped with fewer guns and thinner but more comprehensive armor in a trade-off for higher speed and lower cost.

According to the law, one large cruiser was to be built per year, so work began immediately on a follow-on vessel to fulfill the requirement.

[5] The German navy regarded the vessels as good sea boats, with gentle motion when the ships' lower fuel bunkers were full.

The engines were supplied with steam by fourteen coal-fired Dürr water-tube boilers produced by Düsseldorf-Ratinger Röhrenkesselfabrik, which were ducted into three funnels.

[8] The ships also carried twelve 8.8 cm SK L/35 guns for close in defense; these were arranged in groups of four in shielded pivot mounts.

Prinz Adalbert was initially assigned to the IV Scouting Group, and alternated between the North and Baltic Seas for various operations, including cruising with the fleet during the Raid on Yarmouth in early November.

[13] Friedrich Carl was sent to the Cruiser Division of the Baltic Sea commanded by Konteradmiral (Rear Admiral) Ehler Behring, where she served as his flagship.

Behring was ordered to attack the Russian port of Libau, which was believed to be acting as a staging area for British submarines.

[14][15] After the sinking of Friedrich Carl, Prinz Adalbert was transferred to the Cruiser Division and Behring shifted his flag to the vessel.

[13][15] The ship conducted several operations against Russian forces in the southern Baltic in the first half of 1915, including bombardments of Libau and supporting minelayers around the Gulf of Riga.

On 23 October, Prinz Adalbert was steaming some 20 miles west of Libau in company with a pair of destroyers when she was intercepted by the submarine E8.