Sister ship in the context of "Titanic"

Kaiser Wilhelm der Grosse ("Emperor William the Great") was a German transatlantic ocean liner in service from 1897 to 1914, when she was scuttled in battle. She was the largest ship in the world for a time, and held the Blue Riband for the fastest passenger liner crossing of the Atlantic Ocean, until Cunard Line’s RMS Lusitania entered service in 1907. The vessel’s career was relatively uneventful, despite a refit in 1913.

The liner was built in Stettin for Norddeutscher Lloyd, and entered service in 1897. She was the first liner to be a Four funnel liner and is considered to be the first "super liner." The first of four sister ships built between 1903 and 1907 for Norddeutscher Lloyd (the others being Kronprinz Wilhelm, Kaiser Wilhelm II and Kronprinzessin Cecilie), she marked the beginning of a change in the way maritime supremacy was demonstrated in Europe at the beginning of the 20th century.

HMS Agamemnon was one of two Lord Nelson-class pre-dreadnought battleships launched in 1906 and completed in 1908. She was the Royal Navy's second-to-last pre-dreadnought battleship to be built, followed by her sister ship, Lord Nelson. She was assigned to the Channel Fleet when the First World War began in 1914. The ship was transferred to the Mediterranean Sea with Lord Nelson in early 1915 to participate in the Dardanelles Campaign. She made a number of bombardments against Turkish fortifications and in support of British troops. Agamemnon remained in the Mediterranean after the conclusion of that campaign to prevent the German battlecruiser SMS Goeben and light cruiser Breslau from breaking out into the Mediterranean. Agamemnon shot down the German Zeppelin LZ-55 (LZ-85) during a bombing mission over Salonica in 1916. On 30 October 1918, the Ottoman Empire signed the Armistice of Mudros on board the ship while she was anchored at Lemnos in the northern Aegean Sea. She was converted to a radio-controlled target ship following her return to the United Kingdom in March 1919 and began service in 1921. Agamemnon was the last pre-dreadnought in service with the Royal Navy; she was replaced by Centurion at the end of 1926 and sold for scrap in January 1927.

The G- and H-class destroyers were a group of 18 destroyers built for the Royal Navy during the 1930s. Six additional ships being built for the Brazilian Navy when World War II began in 1939 were purchased by the British and named the Havant class. The design was a major export success with other ships built for the Argentine and Royal Hellenic Navies. They were assigned to the Mediterranean Fleet upon completion and enforced the Non-Intervention Agreement during the Spanish Civil War of 1936–1939.

Most ships were recalled home or were sent to the North Atlantic from October to November 1939, after it became clear that Fascist Italy was not going to intervene in World War II. Then they began to escort convoys and patrol for German submarines and commerce raiders. Two ships were lost to German mines in the first six months of the war. Three more were lost during the Norwegian Campaign, one in combat with a German cruiser and two during the First Battle of Narvik in April 1940. The Battle of France was the next test for the destroyers from May to June, with many of the Gs and Havants participating in the evacuation of Dunkirk and the subsequent evacuations of Allied troops from western France. Three ships were sunk, two by bombs and the other by torpedoes. Most of the H-class ships were sent to the Mediterranean in May in case Mussolini decided to attack France and the majority of the surviving Gs were sent to Force H at Gibraltar in July. Two of them, Griffin and Greyhound, participated in the Battle of Dakar, before being assigned to the Mediterranean Fleet with their sister ships. By the end of the year, the ships participated in several battles with the Royal Italian Navy, losing two to Italian mines and torpedoes, while sinking two Italian submarines. The Havants spent most of the war in the North Atlantic on convoy escort duties, losing half their number to German submarines, while helping to sink six in exchange by the end of the war.

HMS Repulse was one of two Renown-class battlecruisers built for the Royal Navy during the First World War. Originally laid down as an improved version of the Revenge-class battleship, her construction was suspended on the outbreak of war because she would not be ready in time. Admiral Lord Fisher, upon becoming First Sea Lord, gained approval for her to resume construction as a battlecruiser that could be built and enter service quickly. The Director of Naval Construction (DNC), Eustace Tennyson-d'Eyncourt, quickly produced an entirely new design to meet Admiral Lord Fisher's requirements and the builders agreed to deliver the ship in 15 months. They did not quite meet that ambitious goal, but the ship was delivered a few months after the Battle of Jutland in 1916. Repulse and her sister ship Renown were the world's fastest capital ships upon completion.

Repulse participated in the Second Battle of Heligoland Bight in 1917, the only combat she saw during the war. She was reconstructed twice between the wars; a reconstruction in the 1920s increased her armour protection and made lesser improvements, while another in the 1930s was much more thorough. Repulse accompanied the battlecruiser Hood during the Cruise of the Special Service Squadron on a round-the-world cruise in 1923 to 1924 and protected international shipping during the Spanish Civil War in 1936 to 1939.

HMS Albion is a landing platform dock originally built for the Royal Navy, the first of the two-ship Albion class. Built by BAE Systems Marine in Barrow-in-Furness, Albion was launched in March 2001 by the Princess Royal. Her sister ship, Bulwark, was launched in November 2001, also from Barrow. Affiliated to the city of Chester and based in Plymouth, she is the ninth ship to carry the name Albion (after Albion, an ancient name of Great Britain), stretching back to the 74-gun 1763 warship, and last carried by an aircraft carrier decommissioned in 1973 after 19 years service. Designed as an amphibious warfare ship, Albion carries troops, normally Royal Marines, and vehicles up to the size of the Challenger 2 main battle tank. She can deploy these forces using four Landing Craft Utility (LCUs) and four Landing Craft Vehicle and Personnel (LCVPs). A flight deck supports helicopter operations.

Albion's future came under review as part of the 2010 Strategic Defence and Security Review. She was the fleet flagship from December 2010 until October 2011, and then again from March 2018 until January 2021. On 20 November 2024 Defence Secretary John Healey announced that both Albion and her sister Bulwark would be withdrawn from service by March 2025.

HMS Renown was the lead ship of her class of battlecruisers of the Royal Navy built during the First World War. She was originally laid down as an improved version of the Revenge-class battleships. Her construction was suspended on the outbreak of war on the grounds she would not be ready in time. Admiral Lord Fisher, upon becoming First Sea Lord, gained approval to restart her construction as a battlecruiser that could be built and enter service quickly. The Director of Naval Construction (DNC), Eustace Tennyson-d'Eyncourt, quickly produced a new design to meet Fisher's requirements and the builders agreed to deliver the ships in 15 months. They did not quite meet that ambitious goal but the ship was delivered a few months after the Battle of Jutland in 1916. Renown, and her sister HMS Repulse, were the world's fastest capital ships upon completion.

Renown did not see action during the war and was reconstructed twice between the wars; the 1920s reconstruction increased her armour protection and made other more minor improvements; the 1930s reconstruction was much more thorough. The ship frequently conveyed royalty on their foreign tours and served as flagship of the Battlecruiser Squadron when Hood was refitting.