Leipzig was the lead ship of her class of light cruisers built by the German navy. She had one sister ship, Nürnberg. Leipzig was laid down in April 1928, was launched in October 1929, and was commissioned into the Reichsmarine in October 1931. Armed with a main battery of nine 15 cm (5.9 in) guns in three triple turrets, Leipzig had a top speed of 32 knots.

Köln was a light cruiser, the third member of the Königsberg class that was operated between 1929 and March 1945, including service in World War II. She was operated by two German navies, the Reichsmarine and the Kriegsmarine. She had two sister ships, Königsberg and Karlsruhe. Köln was built by the Reichsmarinewerft in Wilhelmshaven; she was laid down in August 1926, launched in May 1928, and commissioned into the Reichsmarine on 15 January 1930. She was armed with a main battery of nine 15 cm SK C/25 (5.9-inch) guns in three triple turrets and had a top speed of 32 knots.