Most ships were recalled home or were sent to the North Atlantic from October–November 1939, after it became clear that Fascist Italy was not going to intervene in World War II. Then they began to escort convoys and patrol for German submarines and commerce raiders. Two ships were lost to German mines in the first six months of the war. Three more were lost during the Norwegian Campaign, one in combat with a German cruiser and two during the First Battle of Narvik in April 1940. The Battle of France was the next test for the destroyers from May–June, with many of the Gs and "Havant"s participating in the evacuation of Dunkirk and the subsequent evacuations of Allied troops from western France. Three ships were sunk, two by bombs and the other to torpedoes. Most of the H-class ships were sent to the Mediterranean in May in case Mussolini decided to attack France and the majority of the surviving Gs were sent to Force H at Gibraltar in July. Two of them, and , participated in the Battle of Dakar, before being assigned to the Mediterranean Fleet with their sister ships. By the end of the year, the ships participated in several battles with the Royal Italian Navy, losing two to Italian mines and torpedoes, while sinking two Italian submarines. The "Havant"s spent most of the war in the North Atlantic on convoy escort duties, losing half their number to German submarines, while helping to sink six in exchange by the end of the war.