HMS Dreadnought (1906) in the context of "Dreadnought"

A battleship is a large, heavily armored warship with a main battery consisting of large guns, designed to serve as a capital ship. From their advent in the late 1880s, battleships were among the largest and most formidable warship types ever built, until they were surpassed by aircraft carriers beginning in the 1940s. The modern battleship traces its origin to the sailing ship of the line, which was developed into the steam ship of the line and soon thereafter the ironclad warship. After a period of extensive experimentation in the 1870s and 1880s, ironclad design was largely standardized by the British Royal Sovereign class, which are usually referred to as the first "pre-dreadnought battleships". These ships carried an armament that usually included four large guns and several medium-caliber guns that were to be used against enemy battleships, and numerous small guns for self-defense.

Naval powers around the world built dozens of pre-dreadnoughts in the 1890s and early 1900s, though they saw relatively little combat; only two major wars were fought during the period that included pre-dreadnought battles: the Spanish–American War in 1898 and the Russo-Japanese War of 1904–1905. The following year, the British launched the revolutionary all-big-gun battleship HMS Dreadnought. This ship discarded the medium-caliber guns in exchange for a uniform armament of ten large guns. All other major navies quickly began (or had already started) "dreadnoughts" of their own, leading to a major naval arms race. During World War I, only one major fleet engagement took place: the Battle of Jutland in 1916, but neither side was able to achieve a decisive result.

Pre-dreadnought battleships were sea-going battleships built from the mid- to late- 1880s to the early 1900s. Their designs were conceived before the appearance of HMS Dreadnought in 1906 and their classification as "pre-dreadnought" is retrospectively applied. In their day, they were simply known as "battleships" or else more rank-specific terms such as "first-class battleship" and so forth. The pre-dreadnought battleships were the pre-eminent warships of their time and replaced the ironclad battleships of the 1870s and 1880s.

In contrast to the multifarious development of ironclads in preceding decades, the 1890s saw navies worldwide start to build battleships to a common design as dozens of ships essentially followed the design of the Royal Navy's Majestic class. Built from steel, protected by compound, nickel steel or case-hardened steel armor, pre-dreadnought battleships were driven by coal-fired boilers powering compound reciprocating steam engines which turned underwater screws. These ships distinctively carried a main battery of very heavy guns upon the weather deck, in large rotating mounts either fully or partially armored over, and supported by one or more secondary batteries of lighter weapons on broadside.

The Deutschland class was a group of five pre-dreadnought battleships built for the German Kaiserliche Marine (Imperial Navy), the last vessels of that type to be built in Germany. The class comprised Deutschland, the lead ship, Hannover, Pommern, Schlesien, and Schleswig-Holstein. The ships closely resembled those of the preceding Braunschweig class, but with stronger armor and a rearranged secondary battery. Built between 1903 and 1908, they were completed after the launch of the revolutionary British all-big-gun battleship HMS Dreadnought in 1906. As a result, they were obsolescent before entering service. The ships nevertheless saw extensive service in the High Seas Fleet, Germany's primary naval formation, through the late 1900s and early 1910s, when they were used for training, which included overseas cruises.

Following the start of World War I in July 1914, the German fleet adopted a strategy of raids on the British coast, which the five Deutschland-class ships supported. These operations culminated in the Battle of Jutland on 31 May – 1 June 1916, where all five ships saw action, despite their marked inferiority to British dreadnoughts. Regardless, they intervened to protect the battered German battlecruisers from their British counterparts, allowing them to escape. In the confused night actions, Pommern was torpedoed and sunk by a British destroyer. After the battle, the four surviving ships were removed from front-line service and used for coastal defense through mid-1917. Thereafter, Hannover alone remained on patrol duty, while the rest were used as barracks or training ships. After Germany's defeat, the Treaty of Versailles permitted the postwar navy to retain several old battleships for coastal defense, including the four Deutschland-class ships.

The arms race between Great Britain and Germany that occurred from the last decade of the nineteenth century until the advent of World War I in 1914 was one of the intertwined causes of that conflict. While based in a bilateral relationship that had worsened over many decades, the arms race began with a plan by German Admiral Alfred von Tirpitz in 1897 to create a fleet in being to force Britain to make diplomatic concessions; Tirpitz did not expect the Imperial German Navy to defeat the Royal Navy.

With the support of the Kaiser Wilhelm II, Tirpitz began advancing a series of laws to construct an increasing number of large surface warships. The construction of HMS Dreadnought in 1906 prompted Tirpitz to further increase the rate of naval construction. While some British observers were uneasy at German naval expansion, alarm was not general until Germany's naval bill of 1908. The British public and political opposition demanded that the Liberal government meet the German challenge, resulting in the funding of additional dreadnoughts in 1910 and escalating the arms race.

The Dreadnought hoax was a practical joke pulled by Horace de Vere Cole in 1910. Cole tricked the Royal Navy into showing their flagship, the battleship HMS Dreadnought, to a fake delegation of Abyssinian royals. The hoax drew attention in Britain to the emergence of the Bloomsbury Group, among whom some of Cole's collaborators numbered. The hoax was a repeat of a similar impersonation that Cole and Adrian Stephen had organised while they were students at Cambridge University in 1905.