Filmmaker: Isil Ocal

As part of the Treaty of Lausanne in 1923, Greece and Turkey agreed to uproot two million people in a massive population exchange, the lasting effects of which are still felt by some in both countries today.

The exchangees had to travel on foot, by train and by sea and many of the ships involved in this mammoth operation were full to overflowing. The elderly and the young especially suffered from the terrible travel conditions.

"My mother had to throw my younger sister, who was three or four, into the sea. I don't remember it but that's what my mother told me", says Huseyin Selvi, who had to leave Greece when he was five years old.

At the age of 97, he was able to travel back to the village where he was born. Only since the 1990s has it been possible for the "exchangees" and their families to visit what they see as their ancestral villages in Greece and Turkey.

They left their houses in a mess. Their slippers were on the doorstep and food on the table. The men kept their house keys in their belts because they were so sure of going back home.

Iskender Ozsoy, writer

Numan Toker, a second generation exchangee, also travelled to the village in Greece his late mother was forced out of. "It was my mother's last wish. Now I'll bring water from there, to her grave. I'll bring soil ... She was longing to see it [village] again but never had the chance," Numan says.

His ancestors had lived in Greece for 400-500 years, until the population exchange. Recalling his mother's stories, Numan says, "She cried, laughed and talked about what they used to do. The day they were called back to Turkey and were leaving, they left 500 sheep and their farmland behind. She even left dinner cooking on the stove. They left everything behind."

Population shifts occurred in the early 20th century as old empires disintegrated and new nation-states emerged. But these changes often raised complex questions of identity for the ordinary people caught up in them.

Greek Orthodox Christians and Muslims had lived together under Ottoman rule for centuries, though not always entirely peacefully.

The Greek war of independence from the Ottomans was fought between 1821 and 1832 and the new state of Greece founded. This created tension which increased after the Balkan Wars of 1912 and 1913. Muslims remaining in Greece and the Balkans suffered discrimination and persecution, while Greek Orthodox Christians were expelled by the Ottomans from the Aegean region.

READ MORE: Turkey, Greece and the era of 'Cold Peace'

After the Ottoman defeat in World War I, the victorious allies manoeuvred to divide up their former empire. This was resisted by the Turkish nationalists led by Mustafa Kamal Attaturk who fought the Turkish War of Independence between 1919 and 1923.

At Lausanne in Switzerland, all the parties sat around the conference table in 1922-23. Part of the resulting Treaty of Lausanne involved an agreement between Greece and Turkey to forcibly exchange around 1.5 million Greek Orthodox Christians and a lower number of Muslims in the largest population displacement of modern times.

When the exchangees arrived at their destinations, they often faced serious problems integrating into their new communities - and some of their social, housing and education problems have persisted.

"I couldn't speak any Turkish when I got married", says Nuriye Can who left Greece in 1923 for Turkey. "My mother-in-law used to ask me why I spoke the language of a 'non-believer'. She asked, 'Why don't you speak your father's language?' I did eventually learn Turkish."

READ MORE: Turkey and Greece: old habits die hard

There are now reciprocal visits by both Greek and Turks, as part of a cultural project supported by the European Union and the Foundation of Lausanne Treaty Emigrants.

"I thought it was a debt of honour, a moral obligation to come and kiss the ground where my grandfathers were born," says Evangelia Kiortci who found her grandparents' village. "They didn't make it, nor did my parents but I'm a third-generation refugee, and I've come ... They left for Greece and they've always had this sorrow. They had never had the chance to come back and walk on the same ground. I'm deeply moved."

For Dimitris Dayioglu, a visit to the Turkish village his grandmother was expelled from, was an equally emotional experience. "My grandmother wanted very much to go back. On her deathbed, she said, 'Take me to my homeland, my son, so I can die there.' But I couldn't take her. She died in 1974. Now, I'm going on her behalf to light her lamp in her village," says Dimitris.

While these visits help encourage understanding between today's Turkish and Greek communities, there's no question that the emotional, political and social legacy of the original population exchange has been painful and very hard for many to overcome.

Why did Huseyin return to his home in Greece 92 years later?

Source: Al Jazeera