The German invasion of Greece or Operation Marita (), were the attacks on Greece by Italy and Germany during World War II. The Italian invasion in October 1940, which is usually known as the Greco-Italian War, was followed by the German invasion in April 1941. German landings on the island of Crete (May 1941) came after Allied forces had been defeated in mainland Greece. These battles were part of the greater Balkans Campaign of the Axis powers and their associates.
Following the Italian invasion on 28 October 1940, Greece, with British air and material support, repelled the initial Italian attack and a counter-attack in March 1941. When the German invasion, known as Operation Marita, began on 6 April, the bulk of the Greek Army was on the Greek border with Albania, then a vassal of Italy, from which the Italian troops had attacked. German troops invaded from Bulgaria, creating a second front. Greece received a small reinforcement from British, Australian, and New Zealand forces in anticipation of the German attack. The Greek army found itself outnumbered in its effort to defend against both Italian and German troops. As a result, the Metaxas defensive line did not receive adequate troop reinforcements and was quickly overrun by the Germans, who then outflanked the Greek forces at the Albanian border, forcing their surrender. British, Australian and New Zealand forces were overwhelmed and forced to retreat, with the ultimate goal of evacuation. For several days, Allied troops played an important part in containing the German advance on the Thermopylae position, allowing ships to be prepared to evacuate the units defending Greece. The German Army reached the capital, Athens, on 27 April and Greece's southern shore on 30 April, capturing 7,000 British, Australian and New Zealand personnel and ending the battle with a decisive victory. The conquest of Greece was completed with the capture of Crete a month later. Following its fall, Greece was occupied by the military forces of Germany, Italy and Bulgaria.
Adolf Hitler later blamed the failure of his invasion of the Soviet Union on Mussolini's failed conquest of Greece. German historian Andreas Hillgruber accused Hitler of trying to deflect blame for his country's defeat from himself to his ally, Italy. It nevertheless had serious consequences for the Axis war effort in the North African theatre. Enno von Rintelen, who was the military attaché in Rome, emphasises, from the German point of view, the strategic mistake of not taking Malta.
History
Greco-Italian War
At the outbreak of World War II, Ioannis Metaxas—the nationalist dictator of Greece and former general—sought to maintain a position of neutrality. Greece was subject to increasing pressure from Italy, culminating in the Italian submarine Delfino sinking the cruiser Elli on 15 August 1940. Italian leader Benito Mussolini was irritated that Nazi leader Adolf Hitler had not consulted him on his war policy and wished to establish his independence. He hoped to match German military success by taking Greece, which he regarded as an easy opponent. On 15 October 1940, Mussolini and his closest advisers finalised their decision. In the early hours of 28 October, Italian Ambassador Emanuele Grazzi presented Metaxas with a three-hour ultimatum, demanding free passage for troops to occupy unspecified "strategic sites" within Greek territory. Metaxas rejected the ultimatum (the refusal is commemorated as Greek national holiday Ohi Day) but even before it expired, Italian troops had invaded Greece through Albania. The principal Italian thrust was directed toward Epirus. Hostilities with the Greek army began at the Battle of Elaia–Kalamas, where they failed to break the defensive line and were forced to halt.. Within three weeks, the Greek army launched a counter-offensive, during which it marched into Albanian territory, capturing significant cities such as Korça and Sarandë. Neither a change in Italian command nor the arrival of substantial reinforcements improved the position of the Italian army. On 13 February, General Papagos, the Commander-in-Chief of the Greek army, opened a new offensive, aiming to take Tepelenë and the port of Vlorë with British air support but the Greek divisions encountered stiff resistance, stalling the offensive that practically destroyed the Cretan 5th Division.
After weeks of inconclusive winter warfare, the Italians launched a counter-offensive on the centre of the front on 9 March 1941, which failed, despite the Italians' superior forces. After one week and 12,000 casualties, Mussolini called off the counter-offensive and left Albania twelve days later..
Modern analysts believe that the Italian campaign failed because Mussolini and his generals initially allocated insufficient resources to the campaign (an expeditionary force of 55,000 men), failed to reckon with the autumn weather, attacked without the advantage of surprise and without Bulgarian support. Elementary precautions such as issuing winter clothing had not been taken. Mussolini had not considered the warnings of the Italian Commission of War Production, that Italy would not be able to sustain a full year of continuous warfare until 1949.
During the six-month fight against Italy, the Hellenic army made territorial gains by eliminating Italian salients. Greece did not have a substantial armaments industry and its equipment and ammunition supplies increasingly relied on stocks captured by British forces from defeated Italian armies in North Africa. To man the Albanian battlefront, the Greek command was forced to withdraw forces from Eastern Macedonia and Western Thrace, because Greek forces could not protect Greece's entire border. The Greek command decided to support its success in Albania, regardless of the risk of a German attack from the Bulgarian border. Italian invasion and initial Greek counter-offensive28 October – 18 November 1940 Greek counter-offensive and stalemate14 November 1940 – 23 April 1941
Hitler's decision to attack and British aid to Greece
The United Kingdom was obliged to assist Greece by the Declaration of 13 April 1939, which stated that in the event of a threat to Greek or Romanian independence, "His Majesty's Government would feel themselves bound at once to lend the Greek or Romanian Government... all the support in their power." The first British effort was the deployment of Royal Air Force (RAF) squadrons commanded by Air Commodore John D'Albiac that arrived in November 1940. With Greek government consent, British forces were dispatched to Crete on 31 October to guard Souda Bay, enabling the Greek government to redeploy the 5th Cretan Division to the mainland.
Hitler decided to intervene on 4 November 1940, four days after British troops arrived at Crete and Lemnos. Although Greece was neutral until the Italian invasion, the British troops that were sent as defensive aid created the possibility of a frontier to the German southern flank. Hitler's principal fear was that British aircraft based in Greece would bomb the Romanian oil fields, which was one of Germany's most important sources of oil. As Hitler was already seriously considering launching an invasion of the Soviet Union the next year, this increased the importance of Romanian oil as once Germany was at war with the Soviet Union, Romania would be the Reich'''s only source of oil, at least until the Wehrmacht presumably captured the Soviet oil fields in the Caucasus. As the British were indeed contemplating using the Greek air fields to bomb the Romanian oil fields, Hitler's fears that his entire war machine might be paralyzed for a lack of oil should the Ploești oil fields be destroyed were to a certain extent grounded in reality. However, the American historian Gerhard Weinberg noted: "...the enormous difficulties of air attacks on distant oil fields were not understood by either side at this time; it was assumed on both sides that even small air raids could bring about vast fire and destruction". Furthermore, the massive Italian defeats in the Balkans, the Horn of Africa and North Africa had pushed the Fascist regime in Italy to the brink of collapse by late 1940 with Mussolini becoming extremely unpopular with the Italian people. Hitler was convinced that if he did not rescue Mussolini, Fascist Italy would be knocked out of the war in 1941. Weinberg wrote the continuing Italian defeats "....could easily lead to the complete collapse of the whole system Mussolini had established, and this was recognized at the time; it is not hindsight from 1943". If Italy was knocked out of the war, then the British would be able to use the central Mediterranean again, and the governors of the French colonies in Africa loyal to the Vichy regime might switch their loyalties to the French National Committee headed by Charles de Gaulle. As Hitler had plans to ultimately use the French colonies in Africa as bases for the war against the United Kingdom, the potential loss of Vichy control over its African empire was seen as a problem by him.
Furthermore, after Italy entered the war in June 1940, the danger of Axis air and naval attacks had largely closed the central Mediterranean to British shipping except for convoys to Malta, in effect closing the Suez canal as the British were forced to supply their forces in Egypt via the long Cape route around Africa. The British had made liberating Italian East Africa a priority to end the possibility of Italian naval and air attacks on British shipping in the Red Sea, which assumed greater importance because of the dangers posed to British shipping in the central Mediterranean. In turn, the decision by Field Marshal Archibald Wavell to deploy significant forces to the Horn of Africa while defending Egypt lessened the number of Commonwealth forces available to go to Greece. Although the performance of the Italian armed forces had been less than impressive, from the German perspective denying the British access to the central Mediterranean by stationing Luftwaffe and Kriegsmarine forces in Italy made it crucial to keep Italy in the war. Hitler ordered his Army General Staff to attack Northern Greece from bases in Romania and Bulgaria in support of his master plan to deprive the British of Mediterranean bases.
On 12 November, the German Armed Forces High Command (OKW) issued Directive No. 18, in which they scheduled simultaneous operations against Gibraltar and Greece for the following January. On 17 November 1940, Metaxas proposed a joint offensive in the Balkans to the British government, with Greek strongholds in southern Albania as the operational base. The British were reluctant to discuss Metaxas' proposal, because the troops necessary for implementing the Greek plan would seriously endanger operations in North Africa. In December 1940, German ambitions in the Mediterranean underwent considerable revision when Spain's leader General Francisco Franco rejected the Gibraltar attack. Consequently, Germany's offensive in southern Europe was restricted to the Greek campaign. The OKW issued Directive No. 20 on 13 December 1940, outlining the Greek campaign under the code designation Operation Marita. The plan was to occupy the northern coast of the Aegean Sea by March 1941 and to seize the entire Greek mainland, if necessary. To attack Greece would require going through Yugoslavia and/or Bulgaria. The Regent of Yugoslavia for the boy king Peter II, Prince Paul was married to a Greek princess and refused the German request for transit rights to invade Greece. Tsar Boris III of Bulgaria had long-standing territorial disputes with Greece, and was more open to granting transit rights to the Wehrmacht in exchange for a promise to have the parts of Greece that he coveted. In January 1941, Bulgaria granted the transit rights to the Wehrmacht.