'OB' (i) was a British naval operation to provide air cover for the shipping and troops at Narvik during the Norwegian campaign (11/18 May 1940)., On 11 May, the fleet carrier... Read More

'OB' (ii) was the designation of Allied convoys (together with a numerical and sometimes a literal suffix) plying from Liverpool out into the Atlantic (September 1939/August 1... Read More

'Oboe I' was the Australian seizure of Tarakan island in Japanese-occupied Borneo within the overall scheme of the 'Montclair' plan (1 May/24 June 1945)., 'Oboe I' was the fir... Read More

'Oboe II' was the Australian seizure of Balikpapan, toward the southern end of Borneo’s eastern side, within the overall 'Montclair' plan (1/10 July 1945)., In 1941 Balikpap... Read More

'Oboe III' was an Allied unrealised plan for Major General George F. Wootten’s Australian 9th Division of Lieutenant General Sir Leslie Morshead’s Australian I Corps to la... Read More

'Oboe IV' was the Allied unrealised plan for what was to have been the most important single element of the 'Oboe' series, namely the Australian recapture the Soerabaja area o... Read More

'Oboe V' was an Allied unrealised plan for elements of Lieutenant General Sir Leslie Morshead’s Australian I Corps to retake British Borneo and to consolidate the Allied hol... Read More

'Oboe VI' was the Australian seizure of Brunei Bay on the north-western corner of Japanese-occupied Borneo as the final Australian contribution to the overall 'Montclair' plan... Read More

'Obviate' was a British air attack on the German battleship Tirpitz at her forward base in German-occupied Norway (29 October 1944)., The attack was undertaken by Royal Air Fo... Read More

'OC' was the designation of Allied convoys (together with a numerical suffix) plying the route from Melbourne to Newcastle, Australia, and as such reciprocals of the 'CO' seri... Read More

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'Ochsenkopf' was a German offensive by Generaloberst Hans-Jürgen von Arnim’s (from 28 February General Gustav von Vaerst’s) 5th Panzerarmee to enlarge and secure the Axis... Read More

'Ochsenkopf' (ii) was the German overall designation of 'Ochsenkopf' (i) and 'Ausladung' as a joint operation, and used in this sense by German higher command echelons (Februa... Read More

'Octagon' was the Allied 2nd Quebec Conference, a political and military conference between President Franklin D. Roosevelt and Prime Minister Winston Churchill, each supporte... Read More

'Octavius' was a British unrealised plan for the concentration of land forces in Turkey in the event that the latter joined the Allies or was invaded by Axis forces (May 1942)... Read More

'Octopus' was an Allied unrealised plan for the secure the Sunda Strait area by taking the flanking western end of Java and eastern end of Sumatra islands in the Japanese-occu... Read More

'Oder' (i) was a German naval minelaying operation in direct succession to 'Pommern' from Stavanger in German-occupied Norway (28/30 January 1941)., The operation was undertak... Read More

'Oder' (ii) was a U-boat wolfpack operation in the Atlantic against the HX.238 convoy (17/19 May 1943)., The wolfpack comprised U-221, U-228, U-336, U-558, U-603, U-642, U-666... Read More

The 'Odessa Defensive Operation' was the Soviet unsuccessful undertaking to hold the Ukrainian port city of Odessa on the north-western coast of the Black Sea (8 August/16 Oct... Read More

'Odin' was the German codeword, analogous to 'Walküre' for commitment only within Germany, to trigger the launch of security measures for military establishments, key politic... Read More

'Odysseus' was the German movement of the newly completed ex-Italian torpedo boats TA 37, TA 38 and TA 39 from Trieste at the head of the Adriatic Sea via the Strait of Otrant... Read More

'Offspring' (i) was a British unrealised plan for heavy bomber attacks on the German battle-cruisers Scharnhorst and Gneisenau, together with the heavy cruiser Prinz Eugen, an... Read More

'Offsrpring' (ii) was a British naval air attack and minelaying operation in the North Sea and Norwegian Sea by a detachment of Admiral Sir Henry Moore’s Home Fleet (9/15 Au... Read More

'OG' was the designation of Allied convoys (together with a numerical suffix) plying the route from the UK (later only Liverpool) south to Gibraltar, and as such reciprocals o... Read More

'Oiled' was the British first attempt to bomb the German battleship Tirpitz in Norwegian waters (30 January 1942)., At 00.30 on 30 January seven Short Stirling heavy bombers o... Read More

'Oktoberfest' was a German and Croat operation against the partisan forces of Marshal Josip Broz Tito in the Bilo mountain area of the puppet state of Croatia in German-occupi... Read More

'OL' was the designation of Allied ocean outward convoys (together with a numerical suffix) plying the route from Liverpool to the west for dispersal (September/October 1940).... Read More

'Oldenburg' (i) was a German programme of clandestine long-range and high-altitude aerial reconnaissance sorties to locate the primary Soviet road and railway lines, industria... Read More

'Oldenburg' (ii) was the German capture of Oslo, the capital of Norway, by the forces of Konteradmiral Oskar Kummetz’s Gruppe V, within 'Weserübung' (9/10 April 1940)., Gru... Read More

This was the German plan for the economic exploitation of lands conquered in the east (spring 1941/summer 1944)., The plan was drafted by General Georg Thomas, head of the Def... Read More

'Olive' (ii) was a British operation within 'Aerial' for the movement of the 3,224-ton Royal Scotsman, carrying 2,800 troops, from the estuary of the Loire river to Falmouth (... Read More

'Olive' (iii) was the British operation by Lieutenant General Sir Oliver Leese’s 8th Army in Italy to break through the German defences of the 'Gotisch-Linie' (25 August/21 ... Read More

'Olivenbaum' was the German predecessor to 'Antimon' for the delivery of war matériel to Romania (27 March 1944 onward). ... Read More

'Olivenernte' was a German unrealised portion of 'Ochsenkopf' (i) for the capture of Medjez el Bab in Tunisia by Generalleutnant Friedrich Weber’s Korpsgruppe 'Weber' of Gen... Read More

'Olymp' was a German operation against partisan forces in the Mt Olympos region of Axis-occupied Greece (17 April/4 May 1943). ... Read More

'Olympic' was the US unrealised plan within 'Downfall' for the initial invasion of the Japanese home islands by Lieutenant General Walter C. Krueger’s 6th Army, and schedule... Read More

'OM' was the designation of Allied convoys (together with a numerical and sometimes a literal suffix) plying the route from Oran, Algeria, to Marseille or Toulon, France, and ... Read More

'Omaha' was the US assault beach in 'Neptune' (iii) and 'Overlord' for Major General Leonard T. Gerow’s V Corps of Lieutenant General Omar N. Bradley’s 1st Army in General... Read More

'Omega' was a US deception based on the 'story' that the forces made available by the elimination of the Ruhr pocket would now be used for an offensive straight to Berlin, and... Read More

'Omelette' was a British unrealised special forces operation by the Special Operations Executive to use T. Gulbrandsen as a double agent to deceive the Gestapo over SOE plans ... Read More

'Omnibus' (i) was a British deception plan, implemented by means of messages from double agents, intended to heighten German concerns about a possible British landing on the c... Read More

'Omnibus' (ii) was a British series of small craft and land attack attacks on targets along the northern part of the coast of German-occupied Norway (February/March 1943)., Op... Read More

'ON' (i) was the designation of British convoys (together with a numerical suffix) plying the route between Methil on the Firth of Forth in eastern Scotland to dispersal in No... Read More

'ON' (ii) was the designation of Allied convoys (together with a numerical suffix) plying the route from Liverpool in the UK to Halifax, Nova Scotia, and as such successors to... Read More

'Onboard' was a British naval sweep by destroyers of Vice Admiral Sir Arthur Power’s East Indies Fleet in the Andaman Sea (25/29 March 1945)., Undertaken by Force 70, and th... Read More

'Onion' was a British two-part radio deception within 'Fortitude North' designed to persuade the Germans that the Allies were readying an invasion of Norway rather than of Fra... Read More

'ONM' (i) was the designation of Allied convoys (with a numerical suffix) plying the route between Milford Haven, Wales, and Belfast Lough, Northern Ireland (July 1941/January... Read More

'ONM' (ii) was the designation of Allied medium-speed ocean convoys (together with a numerical suffix) plying the Atlantic route from Liverpool to New York (?). ... Read More

'ONS' was the designation of Allied slow convoys (together with a numerical suffix) plying the route from Liverpool in the UK to Halifax, Nova Scotia, as the slow element of t... Read More