Plan Z
"U-64" was ordered by the "Kriegsmarine" on 16 July 1937 as part of Plan Z and in violation of the Treaty of Versailles. Her keel was laid down on 15 December 1938 by AG Weser in Bremen as yard number 952. She was launched on 20 September 1939 and commissioned on 16 December under the command of "Kapitänleutnant" Georg-Wilhelm Schulz.