World War I broke out In 1914 and Venizelos was in favour of Greece's entry into the war on the side of the Allies while King Constantine, who had ascended the throne in 1913, wanted Greece to remain neutral. This created a conflict which became known as the "dichasmos" (division) . Venizelos's view finally prevailed and Constantine abdicated in favour of his son Alexander. Greece entered the war in its last phase in 1917. After the end of the war Greek territorial claims were dealt with at the treaties of Neuilly (November 27, 1919) and Sevres (August 10, 1920) according to which Greece annexed Eastern and Western Thrace and the islands of Imbros and Tenedos and acquired the right to occupy Smyrna and its coastline on condition that it would be able to incorporate this territory after a referendum. The Dodecanese islands were recognized as Italian possessions and Cyprus as a British possession. Two months after the signature of the treaty, Venizelos was removed from power.

King Constantine returned, followinq a plebiscite (1920) and continued the campaign against Turkey in Smyrna. The Greek army, having lost the support of the Allies, was led to catastrophe The Kemalian army occupied Smyrna and set it on fire on September 9, 1922. The Greeks of Asia Minor were routed and the Treaty of Lausanne imposed an exchange of minority populations between Greece and Turkey and, according to the same treaty, Eastern Thrace was lost to Greece.

1923 saw the beginning of Greece's first Republic which was marked by political instability .King Constantine abandoned the throne and during the rest of this period there was a series of military coups and dictatorships. In 1935, by means of a fraudulent plebiscite, King George II, son of Constantine, returned to Greece and, a few months later, imposed a dictatorship on August 4, 1936 under a retired general, Ioannis Metaxas.

World War II

Greece was still ruled by dictatorship when World War II broke out. But in spite of their differences, the Greeks sided unanimously with the Allies and rejected the Italian ultimatum presented on October 28, 1940 by which Italy sought free passage for its troops. The Greeks were successful in repulsing the attack and drove back the Italians 60 km. beyond the Albanian border. On April 6, 1941, Germany attacked and Hitler's armies marched into Greece. The government and the king went into exile. The "Occupation" was a particularly hard time for Greece. Starvation decimated the population while executions and deportations rounded off the catastrophe. From the very first moments of the occupation a mass resistance movement came into being. In 1941, political personalities, trade union groups, communists and representatives of related political bodies set up the National Liberation Front (EAM) and its military branch (ELAS).

The opposite political side set up Its own resistance organizations the most important of which were EKKA and EDES (National and Social Liberation and National Greek Democratic League). The leaders of ELAS, EKKA and EDES were former officers in the regular army. They organized the armed resistance movement of the Greek people while urban underground groups hampered the task of the conqueror with strikes and sabotage.

In spite of their successes, however, and particularly whenever opposed political organizations got together for some common activity, it became apparent that their permanent union was impossible. The peak moment of united action by ELAS and EDES came with the blowing up of the Gorgopotamos bridge in November 1942 which was a heavy blow to the conqueror.