Karlsruhe was a light cruiser, the second member of the , and served from November 1929 to May 1938, and again from November 1939 to April 1940, seeing action in World War II. She was operated by two German navies, the "Reichsmarine" and the "Kriegsmarine". She had two sister ships, and . "Karlsruhe" was laid down in July 1926 at the "Deutsche Werke" shipyard in Kiel, launched in August 1927, and commissioned into the "Reichsmarine" in November 1929. She was armed with a main battery of nine 15 cm SK C/25 guns in three triple turrets and had a top speed of .