Grom and Błyskawica entered service in 1937, becoming the strongest European destroyers of their time after the latest French ones. With the outbreak of World War II, the destroyers broke through the Baltic to Britain to help escort wartime supply convoys to Poland. However, the convoys were never organized due to the rapid fall of Poland, and Grom came under the command of the British Navy. Being part of it, she took part in the Norwegian campaign. On May 4, 1940, one of Gro...