A turning point in the history of Greece: The German Wehrmacht invaded the country in April 1941. German field marshal Walther von Brauchitsch (center left), commander in chief of the army, is seen here visiting the Acropolis. Liberation of the mainland came in October 1944. Not all Greeks were opposed to the Nazis. But first, a look further back...

In 1453, Constantinople (now Istanbul), the capital of the Byzantine Empire, fell to the Ottomans. Greece thereby came under a centurieslong Ottoman rule. The liberation struggle of the Greeks began in 1821 in the Peloponnese, and the Greek state was established in 1830. Otto von Wittelsbach, second son of the Bavarian King Ludwig I, became its king (1832-1862).

Greece joined the Allies during the First World War. In 1919, with the approval of the victorious powers, they tried to use the Turkish defeat to bring Eastern Thrace and the area of Izmir and its Greek inhabitants under Greek control. In 1922, the Greco-Turkish War ended with the defeat of Greece.

A large-scale exchange of minority populations was agreed upon in the 1923 Treaty of Lausanne. Some 1.5 million Greeks left Turkey for Greece, while around 500,000 Turks left Greece for Turkey. Social unrest also began in Greece after WWI. From 1924 to 1936 the country was politically very unstable.

On August 4, 1936 General Ioannis Metaxas suspended the Greek parliament and constitution to install an authoritarian regime that ruled until April 1941. On October 28, 1940, Metaxas rejected Italian dictator Mussolini's ultimatum to grant Italy access to Greek territory, leading to the Greco-Italian war. After Italy was defeated and pushed back, the German Wehrmacht invaded Greece in April 1941.

From June 1943 to June 1944, the German occupiers reportedly killed more than 20,000 suspected partisans, imprisoned nearly 26,000 more, and shot nearly 5,000 hostages. Altogether 81 percent of Greece's Jews were murdered in the extermination camps Auschwitz and Treblinka. In October 1944 the Nazi-German Wehrmacht was forced to withdraw from Greece.

The Greek Civil War started shortly after World War II, lasting from March 1946 to October 1949. It was the continuation of a conflict that had started in 1943 between the leftist Democratic Army of Greece and the right-wing Greek conservatives and monarchists. The consequences were catastrophic. There were nearly 57,000 dead among the civilian population alone.

After the civil war, it was mainly the Americans who helped the Greeks rebuild the country. Political instability continued into the following years. On April 21, 1967, right-wing army officers (above) seized power in a coup and set up a military dictatorship that lasted until 1974. Politicians, trade unionists and intellectuals were arrested by the thousands, imprisoned and tortured.

After seven years of dictatorship, the junta resigned in July 1974. Former Prime Minister Konstantinos Karamanlis, who lived in exile during the dictatorship, was sworn in as a transitional premier. Free elections were held within the following year, a new constitution was enacted and junta officers were arrested. Greece has been an EU member since 1981 and a member of the Eurozone since 2001.

In late 2014, with the war in Syria approaching its fourth year and Islamic State making gains in the north of the country, the exodus of Syrians intensified. At the same time, others were fleeing violence and poverty in countries such as Iraq, Afghanistan, Eritrea, Somalia, Niger and Kosovo.

Vast numbers of Syrian refugees had been gathering in border-town camps in neighboring Turkey, Lebanon and Jordan since 2011. By 2015, with the camps full to bursting and residents often unable to find work or educate their children, more and more people decided to seek asylum further afield.

In 2015 an estimated 1.5 million people made their way on foot from Greece towards western Europe via the "Balkan route". The Schengen Agreement, which allows passport-free travel within much of the EU, was called into question as refugees headed towards the wealthier European nations.

Tens of thousands of refugees were also attempting the perilous journey across the Mediterranean on overcrowded boats. In April 2015, 800 people of various nationalities drowned when a boat traveling from Libya capsized off the Italian coast. This was to be just one of many similar tragedies - by the end of the year, nearly 4,000 refugees were reported to have died attempting the crossing.

Countries along the EU's external border struggled to cope with the sheer number of arrivals. Fences were erected in Hungary, Slovenia, Macedonia and Austria. Asylum laws were tightened and several Schengen area countries introduced temporary border controls.

Critics of German Chancellor Angela Merkel's "open-door" refugee policy claimed it had made the situation worse by encouraging more people to embark on the dangerous journey to Europe. By September 2016, Germany had also introduced temporary checks on its border with Austria.

In early 2016, the EU and Turkey signed an agreement under which refugees arriving in Greece could be sent back to Turkey. The deal has been criticized by human rights groups and came under new strain following a vote by the European Parliament in November to freeze talks on Turkey's potential accession to the EU.

With anti-immigration sentiment in Europe growing, governments are still struggling to reach a consensus on how to handle the continuing refugee crisis. Attempts to introduce quotas for the distribution of refugees among EU member states have largely failed. Conflicts in the Middle East and elsewhere show no signs coming to an end, and the death toll from refugee sea crossings is on the rise.