The Bismarck class was a pair of fast battleships built for Nazi Germany's Kriegsmarine shortly before the outbreak of World War II.

During the operation, she destroyed the British battlecruiser HMS Hood and damaged the new battleship Prince of Wales in the Battle of the Denmark Strait.

Tirpitz's career was less dramatic; she operated in the Baltic Sea briefly in 1941 before being sent to Norwegian waters in 1942, where she acted as a fleet in being, threatening the convoys from Britain to the Soviet Union.

A series of conceptual designs was begun by the Reichsmarine (Navy of the Realm) in 1932 to determine the ideal characteristics of a battleship built to the 35,000 long tons (36,000 t) limit of the Washington Naval Treaty.

These early studies determined that the ship should be armed with eight 33 cm (13 in) guns, have a top speed of 30 knots (56 km/h; 35 mph), and have strong armor protection.

[4] At the time, the German Navy was constrained by the terms of the Treaty of Versailles that had ended World War I, which restricted battleships to a maximum displacement of 10,000 long tons (10,160 t).

[6] During this period, the naval leadership grappled with a variety of problems, including the strategic and operational use of such a ship and the preferred propulsion system.

[8] The Reichsmarine learned in June 1934 that Italy had decided to build a pair of 35,000-ton battleships armed with 35 cm (13.8 in) guns—the Littorio class—which would surely provoke the construction of similar ships for the French fleet.

With the construction of at least two 35,000-ton battleships within reach, the German naval design staff began work in late October to lay out requirements for armament, armor, and speed.

The similarity led to speculation that the Bismarcks were essentially copies of the earlier ships, though the arrangement of the main battery along with a three-shaft propulsion system were the only shared traits.

The Naval Ordnance Department argued for an increase to 35 cm guns to keep parity with the expected Italian and French ships, which Raeder approved on 19 January.

[11] The design staff were also required to provide sufficient range to the new battleships; they would have to make long voyages from German ports to reach the Atlantic, and Germany had no overseas bases where the ships could refuel.

[17] The displacement of Bismarck and Tirpitz was ultimately limited by the capabilities of existing infrastructure in Kiel and Wilhelmshaven, and the Kaiser Wilhelm Canal, rather than international agreements.

On 11 February 1937, the Construction Office informed Raeder that the ships could not displace more than 42,000 long tons (43,000 t) due to harbor constraints and canal depths.

[18] Admiral Werner Fuchs, the head of the General Command Office of the Oberkommando der Marine, advised Raeder and Hitler that modifications would be necessary to reduce the displacement to ensure the new ships met the legal requirements of the Second London Naval Treaty.

Their steam turbines did not afford the necessary cruising radius for such a role, and many of the decisions made for the ships' armament and armor layout reflect the expectation to fight a traditional naval battle at relatively close range in the North Sea.

[3] Bismarck's and Tirpitz's main battery consisted of eight 38 cm (15 in) SK C/34 guns in four twin turrets, Anton and Bruno in a superfiring pair forward of the superstructure and Caesar and Dora aft.

[3] As with other German large-caliber naval rifles, these guns were designed by Krupp and featured sliding wedge breech blocks, which required brass cartridge cases for the propellant charges.

[60] The British Royal Air Force conducted aerial reconnaissance of the Norwegian fjord in which Bismarck and Prinz Eugen had stopped, to confirm the sighting.

[63] The British ships steamed directly towards Bismarck and Prinz Eugen, before attempting a turn to bring the two forces on a roughly parallel course.

During the turn, at least one of Bismarck's 38 cm shells penetrated one of the aft ammunition magazines aboard Hood, which caused a catastrophic explosion and destroyed the ship.

On the morning of 26 May, a Coastal Command PBY Catalina flying boat spotted Bismarck 690 nmi (1,280 km; 790 mi) to the north-west of Brest; she was steaming at a speed that would put her under the protective umbrella of German aircraft and U-boats within 24 hours.

[71] At approximately 20:30, a flight of fifteen Ark Royal's 820 Naval Air Squadrons Swordfish torpedo bombers launched an attack on Bismarck.

[79] On 14 January 1942, Tirpitz left German waters for Norway, escorted by the destroyers Z4 Richard Beitzen, Z5 Paul Jacobi, Z8 Bruno Heinemann and Z29,[80] arriving at Trondheim on the 17th.

[81] The Germans used the ship as a fleet in being to tie down British naval forces to protect the convoy route to the Soviet Union and to deter an invasion of Norway.

[82] On 6 March, Tirpitz, escorted by the destroyers Z25, Z14 Friedrich Ihn, Z5 Paul Jacobi and Z7 Hermann Schoemann,[80] launched a raid on the British convoys to the Soviet Union.

A Home Fleet squadron consisting of the battleships King George V and Duke of York, the aircraft carrier Victorious, the heavy cruiser Berwick and destroyers failed to find the Germans.

[80] Victorious launched a strike of twelve Fairey Albacore torpedo bombers, however the aircraft were repulsed without having scored any hits on the German ships.

[86] On 6 September, Tirpitz, Scharnhorst, and the destroyers Z27, Z29, Z30, Z31, Z33, Z15 Erich Steinbrinck, Z20 Karl Galster, Z10 Hans Lody and Z6 Theodor Riedel bombarded the island of Spitzbergen, which served as a British refueling station.

[90] The first attack, Operation Paravane, came on 15 September, when a force of 27 Lancasters dropped a single Tallboy each; the bombers succeeded in hitting Tirpitz directly in the bow with one of the bombs.