From the restoration of the monarchy to the end of the civil war (1935–49): In June 1935 the royalists won a major electoral victory. After the removal of the moderate royalist Prime Minister Tsaldaris, radical supporters of the monarchy proclaimed the monarchy on October 12, 1935 and had this confirmed by a plebiscite on November 3, 1935 after extensive electoral manipulation. When King George II, who had returned to Greece, was unable to unite the conflicting forces, Prime Minister I set up Metaxas with his approval(1936–41) established a dictatorial system of government (“Dictatorship of August 4, 1936”), which was based on fascist regimes, but which could also refer to economic successes and significant social policy measures (e.g. minimum wages, collective agreements, social insurance). In terms of foreign policy, Metaxas combined neutral restraint with reference to the Western powers (Great Britain, France). In anticipation of a Bulgarian attack, the northern border was heavily fortified (“Metaxas Line”).

The incursion of the Italian armed forces (October 28, 1940) into the Greek city of Epirus drew Greece into the Second World War. Although the Greek troops succeeded in repelling the Italian attack and, in return, advancing into the territory of Albania (occupied by Italy in 1939 and annexed to it), they had to face the German 12th Army, which invaded from Bulgaria on April 6, 1941, who quickly broke through the “Metaxas Line” surrendered on April 21, 1941 (repetition of the surrender with the participation of Italy on April 23, 1941 in Thessaloniki). The British expeditionary force, which landed in Greece in March 1941 as a result of a Greek request for help, withdrew again. On April 27, 1941, German troops entered Athens; German paratroopers and mountain troops conquered Crete from May 20th to June 1st, 1941.

While George II and the government under Prime Minister Emmanuel Tsuderos (* 1882, † 1956) went into exile, Greece was initially largely subordinated to an Italian military administration; after the capitulation of Italy (1943), German troops occupied the country. Governments that cooperated closely with the occupying powers were in office in 1941/42 under General Giorgios Tsolakoglu (* 1887, † 1948), 1942/43 under Konstantinos Logothetopoulos (* 1878, † 1951) and 1943/44 under Ioannis Rallis (* 1878, † 1951). The terrorist actions and excesses of German occupation organs against the Greek population (hostage shootings and mass executions; e.g. in the village of Komeno on August 16, 1943, in Kalavryta on December 13, 1943, in Distomo on June 10, 1943) remained in the consciousness of the people 1944, as well as the massacre of at least 3 760 Italian prisoners of war on Kefallinia in September 1943). In 1943/44 Greek Jews were also deported to the extermination camps in Eastern Europe. Resistance organizations formed against the occupying powers, v. a. the E. A. M. whose military organization ELAS waged an effective partisan war against the occupiers and was soon able to bring large parts of the country under their control (on March 10, 1944, establishment of a provisional government [Political Committee of National Liberation, Greek abbreviation PEEA] and one month later implementation of Elections in the areas exempted from it). In addition, there was the much smaller, but by the British patronized republican-conservative E. D. E. S. (Greek abbreviation for National Democratic Greek League). Both resistance organizations fought bitterly. The ideological contradictions carried over to the Greek armed forces in Egypt, where left-wing officers started a mutiny in April 1944. The former Venizelist reached the Lebanon Conference (May 17-20, 1944) G. Papandreu that all parties and resistance organizations recognized the authority of the government in exile under his leadership (May to December 1944). Probably under pressure from Moscow, in the Caserta Agreement (September 26, 1944), the partisan associations submitted to the government and the command of the British General Ronald Scobie (* 1893, † 1969). When the German Wehrmacht units withdrew (October / November 1944), the Papandreu government entered Athens on October 18, 1944, under the protection of the British troops landing in Greece. Government of National Unity «) also included ministers from the ranks of the EAM (resignation after the order to disarm the ELA S). The uprising in Athens triggered by the Communists on December 3, 1944, which started a civil war that lasted until 1949, was suppressed by the British troops that intervened on December 5, 1944 (armistice on January 11, 1945, on December 12, 1944). 2. 1945 peace agreement with the EAM in Varkiza). At the end of December 1944 W. Churchill (* 1891, † 1949) personally traveled to Athens and had won the appointment of the popular Athens Archbishop Damaskinos (* 1891, † 1949) as regent. After the parliamentary elections of March 31, 1946, which were boycotted by the Communist Party, K. Tsaldaris took over the post of Prime Minister in April 1946 (until January 1947 and again from August to September of the same year) and worked to restore the monarchy. The Greek communists opposed this restoration (which was accompanied by tough crackdown on the left opposition); on October 28, 1946, their partisan groups united under the command of Markos Vafiadis (* 1906, † 1992) to the “Democratic Army of Greece”, which took up armed struggle with Albanian, Bulgarian and Yugoslav support. Above all with the help of the USA, which replaced Great Britain as a protecting power under the Truman Doctrine in 1947, the newly armed government troops put down the uprising after several years of bloody conflict and forced the “Provisional Democratic Government” formed on December 28, 1947 for those of the Communists controlled areas in October 1949 to give up all military action (afterwards years of persecution of those involved in the uprising, numerous death sentences and thousands of arrests).

The Italian and German attacks on Greece during World War II, the occupation and the civil war left hundreds of thousands dead; many Greeks left the country during the turmoil of the civil war. In the Peace of Paris (February 10, 1947) Greece won the Dodecanese.