Z21 "Wilhelm Heidkamp" was one of six Type 1936 destroyers built for the "Kriegsmarine" (German Navy) in the late 1930s. Completed a few months before the start of World War II in September 1939, the ship served as a flagship throughout her career. She briefly patrolled the Skagerrak where she inspected neutral shipping for contraband goods. "Z21 Wilhelm Heidkamp" later helped to laid four offensive minefields off the English coast that claimed two British destroyers, 2 fishing trawlers, and twenty-seven merchant ships. During the German invasion of Norway in April 1940, she sank a Norwegian coastal defense ship off Narvik and was crippled with the opening shots of the First Naval Battle of Narvik on 10 April, with the loss of 81 crewmen. The ship sank the following day.