moved, this time to command of the 4th Destroyer Flotilla, the famous s. The leader's ship at the time was but as she was due for a refit he swapped ships to take over . Altmark In February 1940, Vian's flotilla was ordered to find and locate the German supply tanker, . This ship was believed to be holding around 300 British merchant seamen captured by . When found, Altmark was in neutral Norwegian waters, escorted by two Norwegian torpedo boats. After peacefully negating the Norwegian opposition, Vian pursued Altmark into Jøssingfjord, she was boarded and the captives were freed. The German and Norwegian governments protested that this was a violation of international law and of Norwegian neutrality. However, occurring during a quiet stage in the war, the incident was widely publicised in Britain. Vian was awarded the Distinguished Service Order (DSO) for this successful action, the citation was published in a supplement to the London Gazette of 9 April 1940 (dated 12 April 1940, and read: Naval actions The Germans invaded Norway on 9 April 1940 and Vian, now in Afridi, was engaged in a number of operations against German shipping and warships and in support of Allied troops. On 9 April 1940, Vian's destroyers were escorting two cruisers ( and ) off Bergen when they came under heavy German air attack. became isolated and was sunk. From 15 to 17 April, Afridi assisted and protected British troop landings at Namsos (Operation Maurice), which were a part of a planned pincer movement to seize Trondheim. Afridi later assisted the evacuation of Namsos and the rescue of the survivors of the , during which, on 3 May, Afridi was bombed and sunk; the survivors were rescued by destroyers and . Vian was Mentioned in Despatches for his part in the action. On the night of 13/14 October, Vian, now re-established in HMS Cossack and with HMS Ashanti, Maori and Sikh, attacked a small German convoy off Egerö light. Although the operation's success was over-stated (just one ship was sunk and later refloated), Vian was awarded a bar to his DSO. On 22 May 1941, Vian, in HMS Cossack, with several destroyers, provided additional escort to troop convoy WS8B en route from Glasgow to the Indian Ocean. On 25 May, Vian's destroyers (HMS Cossack, Maori, Sikh, Zulu and ) were detached from the convoy to join the search for the German