SMS Medusa was a member of the ten-ship Gazelle class of light cruisers that were built for the German Kaiserliche Marine (Imperial Navy) in the late 1890s and early 1900s.

Built to be able to serve with the main German fleet and as a colonial cruiser, she was armed with a battery of ten 10.5 cm (4.1 in) guns and a top speed of 21.5 knots (39.8 km/h; 24.7 mph).

Medusa was among the six light cruisers Germany was permitted to retain under the terms of the Treaty of Versailles, and she was the first major warship to return to service in 1920; as a result, she served as the Reichsmarine's flagship until relieved by the battleship Hannover in 1921.

Her career in the early 1920s followed a similar pattern to her prewar years, being occupied with training exercises and visits to foreign ports.

She was decommissioned for the last time in 1924 and subsequently used as a barracks ship until 1940, when during World War II, she was converted into a floating anti-aircraft battery.

Based outside Wilhelmshaven, she helped to defend the port for the rest of the war, before being badly damaged in an air raid in April 1945.

Following the construction of the unprotected cruisers of the Bussard class and the aviso Hela for the German Kaiserliche Marine (Imperial Navy), the Construction Department of the Reichsmarineamt (Imperial Navy Office) prepared a design for a new small cruiser that combined the best attributes of both types of vessels.

Medusa carried 560 t (550 long tons) of coal, which gave her a range of 3,560 nautical miles (6,590 km; 4,100 mi) at 10 knots (19 km/h; 12 mph).

[4][7] Medusa was finally commissioned for active service on 1 April 1903, under the command of Korvettenkapitän (KK—Corvette Captain) William Kutter, thereafter joining the reconnaissance screen for I Battle Squadron.

The next year, she was present for a naval review in the Kieler Förde for King Edward VII of Great Britain during his visit to Germany.

[8] The year 1907 passed uneventfully for Medusa, apart from during the annual fleet maneuvers on 7 September, when the ship suffered a machinery breakdown, forcing her to return to Kiel for repairs.

[9] Following the outbreak of World War I in July 1914, Medusa was recommissioned on 4 August, under the command of FK Erich von Zeppelin.

She was not decommissioned, however, and over the course of 30 November – 1 December, her crew was replenished and she was ordered to replace her sister Undine, which had been torpedoed and sunk in the western Baltic Sea.

By the end of the year, the naval command decided to withdraw Medusa from service, owing to her obsolescence in the face of modern weapons and to worsening crew shortages.

At that time, she was assigned to the Marinestation der Ostsee (Baltic Sea Naval Station), which also included two torpedo boat flotillas and the survey ship Triton.

She later visited foreign ports between 30 August and 5 September, including Fårösund and Visby on the island of Gotland in Sweden.

Medusa then made another series of visits to ports in the Baltic between 28 July and 2 August, including Uddevalla and Gothenburg, Sweden.

In September, KK Ernst Meusel replaced Werth as the ship's captain; he was to be the vessel's last commanding officer.

[13] From 1 February 1928, Medusa began to serve as a barracks ship for torpedo boat and destroyer crews in Wilhelmshaven.

In July 1940, during World War II, Medusa was converted into a floating anti-aircraft battery at the Rickmers Reederei shipyard in Bremerhaven.