The Occupation of Iceland during World War II began with a British invasion in order to occupy the island and deny it to Germany. The military operation, codenamed Operation Fork, was conducted by the Royal Navy and Royal Marines. The British forces were later replaced by Canadian and then American forces, even though the United States was not yet in the war.

Invasion

The invasion of Iceland was a British military operation conducted by the Royal Navy and Royal Marines during World War II to occupy Iceland and deny it to Germany. At the start of the war, Britain imposed strict export controls on Icelandic goods, preventing profitable shipments to Germany, as part of its naval blockade. Britain offered assistance to Iceland, seeking cooperation "as a belligerent and an ally", but Reykjavík declined and reaffirmed its neutrality. The German diplomatic presence in Iceland, along with the island's strategic importance, alarmed the British. On 9 April 1940, Germany overran Denmark, Iceland's former mother country, whose king was still the Icelandic head of state. After failing to persuade the Icelandic government to join the Allies, the British invaded on the morning of 10 May. The initial force of 746 British Royal Marines, commanded by Colonel Robert Sturges, disembarked at the capital Reykjavík. Meeting no resistance, the troops moved quickly to disable communication networks, secure strategic locations, and arrest German citizens. Requisitioning local transport, the troops moved to Hvalfjörður, Kaldaðarnes, Sandskeið, and Akranes to secure landing areas against the possibility of a German counterattack.

On the evening of 10 May, the government of Iceland issued a protest, charging that its neutrality had been "flagrantly violated" and "its independence infringed", and noting that compensation would be expected for all damage done. The British promised compensation, favourable business agreements, non-interference in Icelandic affairs, and the withdrawal of all forces at the end of the war. Resigning themselves to the situation, the Icelandic authorities provided the invasion force with de facto cooperation, though formally maintaining a policy of neutrality. In the following days air defence equipment was deployed in Reykjavík and a detachment of troops sent to Akureyri. The initial invasion force was ill-equipped, only partially trainedBittner 41. and insufficient for the occupation and defence of the island. On 17 May, 4,000 additional troops of the British Army arrived to relieve the marines. In July, elements of the 2nd Canadian Division and 3rd Canadian Division were landed. Commonwealth occupation forces eventually totalled 25,000 infantry with support elements from the Royal Air Force, Royal Navy and Royal Canadian Navy. One year after the invasion, military forces from the still officially neutral United States were stationed on the island by agreement with the Icelandic government, relieving the bulk of British ground forces. U.S. forces grew considerably after the U.S. entered the war on 11 December 1941, reaching up to 30,000 Army (including Air Force personnel) and Navy personnel at any one time. The RAF and RCAF continued to operate from two Royal Air Force stations through to the end of the war.

Occupation British occupation

Under Brigadier George Lammie, Alabaster Force was formed to permanently occupy Iceland and fortify the island's defence. On 17 May 1940, the British 146th Infantry Brigade, arrived to relieve the Royal Marine invasion force, who left 19 May. Stretched thin, Brigadier Lammie requested additional forces of the HQ of the 49th (West Riding) Infantry Division, a Territorial Army (TA) formation under Major General Henry Curtis, and the 147th Brigade arrived on 26 May, followed by numerous convoys of troops and supplies. The Prime Minister, Winston Churchill, on his way home from visiting President Roosevelt, visited British occupation troops in 1940, and suggested the creation of a mountain and snow warfare school. Elements based in Akureyri formed the Tactical School, Winter Warfare Course which trained the 49th into a Mountain/Arctic division. The 49th Division adopted a new divisional insignia, featuring a polar bear standing on an ice floe. Additional reinforcements over the course of the summer included field artillery, anti-aircraft guns, Bren Gun Carriers, engineer and construction units, and support forces. The final British ground reinforcements, an infantry battalion and artillery battery, arrived in June 1941. By July 1941, there were over 25,000 British troops on the island.

Construction of airfields (including what became Reykjavík Airport), harbours, roads and other facilities began immediately. Hvalfjörður became a naval base for merchant escort and anti-submarine forces, with extensive facilities including a mine depot, pier and jetties, accommodation, a fresh water system, ammunition storage, a fleet bakery, bulk naval storage warehouse, recreation facilities, a direction-finding station and a fuel farm. The facility was protected by a minefield, anti-submarine gate and boom across the fjord, coastal guns, AA batteries, and anti-submarine trawlers. The Royal Navy Fleet Air Arm 701 Naval Air Squadron provided initial air support, and the army built two airfields, RAF Kaldadarnes and RAF Reykjavik, home to several RAF and RCAF squadrons until the end of the war. As naval base facilities grew, RAF Coastal Command aircraft were stationed for patrol, reconnaissance, and anti-submarine duties. The cruiser and the battleship visited Akureyri harbour in May 1941, just before their sea battle with the German warships and in the Denmark Strait between Greenland and Iceland. The hospital ship Leinster, based at Akureyri harbour, sailed on 24 May to care for the wounded after the destruction of in the battle. Two hospitals were also built: No. 50 General Hospital was built at Reykjavík and operated from June 1940 to March 1942; No. 30 General Hospital operated from July 1940 to September 1941.

At the end of hostilities most British facilities were turned over to the Icelandic government. 199 Commonwealth soldiers are buried in Iceland in six cemeteries cared for by the Commonwealth War Graves Commission.

British Army 49th (West Riding) Infantry Division 70th Infantry Brigade 10th Battalion, Durham Light Infantry 11th Battalion, Durham Light Infantry 1st Battalion, Tyneside Scottish 147th Infantry Brigade 1/6th Battalion, Duke of Wellington's Regiment 1/7th Battalion, Duke of Wellington's Regiment 1/5th Battalion, West Yorkshire Regiment 146th Infantry Brigade 4th Battalion, Lincolnshire Regiment 1/4th Battalion, King's Own Yorkshire Light Infantry Hallamshire Battalion, York and Lancaster Regiment Divisional Troops 2nd Battalion, Princess Louise's Kensington Regiment 69th (West Riding) Field Regiment, Royal Artillery 143rd (Kent Yeomanry) Field Regiment, Royal Artillery 294th Field Company, Royal Engineers 756th Field Company, Royal Engineers 757th Field Company, Royal Engineers 289th Field Park Company, Royal Engineers 23rd Bridging Platoon, Royal Engineers 49th (West Riding) Divisional Signals Regiment, Royal Corps of SignalsRoyal Navy

HMS Lancaster

HMT Franconia HMT Lancastria

HMT Ulster Prince HMHS LeinsterRoyal Air Force No. 48 Squadron No. 53 Squadron No. 86 Squadron No. 98 Squadron No. 120 Squadron No. 204 Squadron No. 209 Squadron No. 210 Squadron No. 221 Squadron No. 269 Squadron No. 279 Squadron No. 280 Squadron No. 330 Squadron No. 612 (County of Aberdeen) Squadron No. 1407 (Meteorological) Flight

Canadian occupation

On 18 May 1940, Britain requested Canada to garrison and defend Iceland with the 2nd Canadian Division, along with air force, anti-air, shore battery and coastal defence elements. "Z" Force, led by Brigadier L. F. Page, with part of his brigade headquarters and the Royal Regiment of Canada embarked on the on 10 June, and landed at Reykjavik on 16 June 1940. The remainder of the 2,659 man "Z" Force, comprising the Fusiliers Mont-Royal, the Cameron Highlanders of Ottawa (M.G.), a brigade signal section and details, arrived on 9 July. Canadian forces dispersed across the island and initiated work on defence positions, and preparations for the building of the aerodrome in Kaldaðarnes, building roads, improving harbours, establishing guard over strategic assets, and setting up coast watch stations. On 9 February 1941, Canadian forces engaged a single German aircraft overflying the island.

Owing to pressing needs elsewhere including Canadian commitments to the defence of Britain, and to providing garrison troops in the West Indies, it was agreed to redeploy Canadian forces. Force headquarters and the Royal Regiment sailed for England on 31 October and rejoined the main body of the 2nd Canadian Division. The Camerons, who had been allotted to the 3rd Division, spent the winter on the island and departed for England on 28 April 1941. They were temporarily replaced by British garrison forces, until 7 July 1941, when the defence of Iceland was transferred from Britain to the (still officially neutral) United States, by agreement with Iceland. Canadian army, navy and air force units were dispatched to and continued to operate in and around Iceland throughout the war. No. 162 Squadron RCAF was seconded to RAF Coastal Command and stationed at RAF Reykjavik from January 1944 to cover the mid-ocean portion of the North Atlantic shipping route. Aircraft from this squadron attacked two U-boats in 1944, sinking on 17 April 1944. Canadian Army 4th Canadian Infantry Brigade The Royal Regiment of Canada (rifle battalion) Les Fusiliers Mont-Royal (rifle battalion) The Cameron Highlanders of Ottawa (MG) (machine gun battalion) Royal Canadian Navy

Merchant Navy

SS Tregarthen SS Stonepool SS Dracola SS Yearwood Royal Canadian Air Force No. 162 Squadron RCAF RCAF Marine Craft Beaver RCAF Marine Craft Eskimo

United States occupation

Britain needed its troops elsewhere, and requested that US forces occupy the island. The US agreed on 16 June 1941. The 1st Provisional Marine Brigade of 194 officers and 3,714 men from San Diego under the command of Brigadier General John Marston sailed from Charleston, South Carolina on 22 June to assemble as Task Force 19 (TF 19) at Argentia, Newfoundland: TF 19 sailed on 1 July. Britain failed to persuade the Althing to approve an American occupation force, but with TF 19 anchored off Reykjavík that evening Roosevelt gave approval for the invasion. The United States Marine Corps commenced landing on 8 July, and disembarkation was completed on 12 July. On 6 August, the United States Navy established an air base at Reykjavík with the arrival of Patrol Squadron VP-73 PBY Catalinas and VP-74 PBM Mariners. United States Army personnel began arriving in Iceland in August.

US Marines 1st Provisional Marine Brigade 5th Marine Defense Battalion 6th Marine Regiment (United States) 1st Battalion 6th Marines 2nd Battalion 6th Marines 3rd Battalion 6th Marines 2nd Battalion 10th Marines A Company of the 2nd Tank Battalion A Company of the 2nd Service Battalion

US Army Air Force 33rd Pursuit Squadron 24th Special Operations WingUS Army 5th Infantry Division Division Headquarters 2nd Infantry Regiment 10th Infantry Regiment 11th Infantry Regiment 5th Division Artillery 19th Field Artillery Battalion, (18x 105mm Howitzers) 46th Field Artillery Battalion, (18x 105mm Howitzers) 50th Field Artillery Battalion, (18x 105mm Howitzers) 21st Field Artillery Battalion, (18x 155mm Howitzers) 7th Combat Engineer Battalion 5th Reconnaissance Troop (Mechanized) 5th Medical Battalion Special Troops 705th Ordnance Light Maintenance Company 5th Quartermaster Company 5th Signal Company Military Police Platoon Band 61st Coast ArtilleryUS Navy

VP-73 (United States Navy)

Outcome