MIDYAT, Turkey (Reuters) - When Louis Bandak fled the violence in Syria, he sought refuge in the country his grandfather was forced to abandon exactly 90 years ago this week.

Bandak, his wife and two daughters are part of a small but growing trickle of Christians arriving in Turkey after three years of civil war in Syria killed more than 140,000 people.

"Although I had never been here before, it does not feel strange. This too is my homeland," says Bandak, sitting in warm winter sun outside the 5th Century Mor Abrohom Monastery in Midyat, 30 miles (50 km) north of the border.

While most Christian refugees are in Lebanon or Jordan, countries with which they share linguistic or cultural ties, several thousand have come to Turkey. For many it is a reversal of their ancestors' flight around a century ago, when World War One and the subsequent building of the post-Ottoman Turkish state made Turkey a hostile land for millions of Christians.

The sectarian strife that has rent apart Syria's delicate multi-ethnic fabric has spawned a severe humanitarian crisis and driven 2.5 million refugees into neighbouring countries.

Turkey has taken in 700,000 mostly Sunni Muslim refugees.

The United Nations does not register Syrian refugees by religion so cannot give an exact figure for Christians who have left, but estimates vary between 300,000 and 500,000, says Mark Ohanian, director of programmes of the International Orthodox Christian Charities, which works inside Syria.

Their flight has been driven in part because Christians, seen as largely supportive of President Bashar al-Assad, have been targeted by rebels in some parts of Syria and feel threatened by increasingly hardline Islamist fighters.

Some have sought safety in mountain villages in Iraq's stable Kurdish-run north, and about 20,000 ethnic Armenians have resettled in Armenia, Ohanian said.

Syria's total Christian minority, which made up about 10 percent of the pre-war population of 22 million, has generally kept to the sidelines of the war, which pits mainly Sunni Muslim rebels against Assad, who is from the minority Alawite sect, and his foreign Shi'ite allies.

Bandak is Syriac, a people who number about 180,000 in Syria and survive in pockets of Iraq, Iran and Turkey. Many still speak a dialect of Aramaic, the language of Christ.

SMUGGLED TO EUROPE

Christians are exiting through Turkey because its border with Europe offers a better chance of eventual asylum there, says Sait Susin, chairman of the Syriac Orthodox Foundation in Istanbul, which relies on donations from the local community to house and feed 500 of its Syrian brethren at a time.

He estimates more than 5,000 Syriacs have passed through Turkey but the precise number is unknown, because most arrive informally and spend anywhere from 10 days to more than a year before moving on. Since late 2012, their numbers have increased steadily as Christians feel a greater threat from an uprising that has grown more radical in outlook, he said.

In a working-class district in Istanbul, about 55 people dwell in a former three-storey home run by Susin's foundation. Another 150 people are on a waiting list for beds.

Entire families cram into small bedrooms, and about 20 or so young men sleep on bunk beds in spartan dormitories. They gather once a day at a nearby Catholic church to share a meal.

Some have applied for visas to European countries, but few are optimistic their paperwork will come through as governments tighten restrictions on asylum seekers from Syria.

Instead, many are scratching together the 10,000 euro ($13,700) fee traffickers demand to smuggle them across the sea to Greece before they unite with relatives further north in Germany or Sweden. This treacherous route is not an option for the elderly and the 13 children staying at the Istanbul house.

Milad, a 24-year-old former conscript who deserted Assad's army after he was seriously wounded last year, is gloomy about his chances of raising the funds for passage to Europe.

Hit by shrapnel last June, he passes his time asleep or strengthening a withered right arm pockmarked with scars, embedded shards of metal and wounds still oozing pus.

"I was caught between two fires in a war that is not mine," says Milad, asking that his surname not be used. "I never wanted to leave my country. Now I can never go back."

EMPTY CAMP

In Midyat, an ancient town of conjoined sandstone houses, the Bandaks are among 500 or so Syrians staying in private homes belonging to Turkish Syriacs who left the area years ago.

All but two Syrian families have snubbed a camp opened last year for Christian Syrians on the grounds of Mor Abrohom.

Gleaming white tents, a hospital and a market stand behind barbed wire in a hollow where monks once raised barley, ready for up to 4,000 people should violence escalate in north Syria.

The Bandaks have languished in Midyat for nine months, their girls unable to attend school. Living off savings and help from the local church, the family awaits visas for Germany where Bandak's wife, Ninorta, has relatives.

Bandak, 48, a bespectacled goldsmith from Aleppo, said he had been determined to stay in Syria's largest city even after its Ottoman-era souk was destroyed and medieval citadel damaged.

The decision to leave came last spring when foreign fighters stopped a bus he had taken to Damascus and lingered over his ID card and his non-Muslim name, then accused him of collaborating with the state.

"I said I was a poor electrician, they let me go. I could not stop shaking. I thought of my daughters without a father."

He locked the family's possessions into one room of their apartment and hired a car to take them to the border with a few suitcases of clothes and a computer hard drive of family photos.

"We have had enough of war. Next time I go to Syria, I'll go as a tourist," Ninorta says.

Hardline Islamists are said to be behind attacks on Christians, spurred by politics or money.

In December, fighters abducted 12 Greek Orthodox nuns from the Christian stronghold of Maaloula.

Earlier in 2013, a Syriac Orthodox bishop and a Greek Orthodox bishop disappeared outside of Aleppo.

"Christians are targeted because they are perceived as being allied with Assad, but also because they are natural targets for religious fundamentalists," says historian William Dalrymple, who has written extensively about imperiled Christian communities in the Middle East, home still to 14 million Christians who trace their roots back two millennia.

Until the war, Syria was a relatively free place for Christian expression, a vestige of a wider Middle East that was more tolerant 50 years ago, Dalrymple says.

"Middle Eastern Christians are going through the period of their biggest decline, and it is irreversible," he said, pointing to the nearly 70 percent drop in Iraq's Christian population since the U.S. invasion of 2003.

Erol Dora, a Syriac and Turkey's first Christian lawmaker in a half-century, says those who leave the region are doing so as a last resort, after they have parted with property.

"By the time they leave, they have usually lost everything, even hope. Their trust that they can be safe again is gone."

HOLY MOUNTAIN

Amid the region's upheaval, Turkey has become a safe haven.

Tur Abdin, or Mountain of the Servants of God, is a high plateau situated between the Tigris and Euphrates Rivers, Syriacs' second-holiest site after Jerusalem.

The centre of one of the world's oldest Christian traditions, some 80 monasteries, most in ruins, dot the landscape of dry scrubland and outcrops.

The arrival of Bandak and other Syriacs has helped swell church pews at Midyat's 1,600-year-old churches.

Poverty and violence between Turks and Kurds in the 1980s and 1990s reduced an already dwindling Syriac population in Tur Abdin to 2,500 from about 50,000 in 1950, said Heidi Armbruster, an anthropologist at the University of Southampton. Istanbul is home to 15,000 Syriacs.

In recent years, Turkey has sought to improve the plight of Syriacs, pledging to return confiscated monastic land and allowing the community to open its first school in 86 years.

Community leaders say Prime Minister Tayyip Erdogan has even extended an invitation to the Syriac Orthodox Patriarchate of Damascus, now in exile in Beirut, to return to Turkey, its seat since 37 A.D. before Turkey expelled it to Syria in 1925.

Bandak speaks a smattering of Turkish taught by his grandfather, Barsom, who abandoned his farm in the Turkish town of Siverek after his father was murdered by Muslim neighbours. Bandak still recalls the exact date Barsom fled: Feb. 24, 1924.

On the wall of the home where Bandak stays is a simple oil painting, a triptych of a charred landscape with ghost-like figures. It depicts "Seyfo," the Year of the Sword in 1915, when historians say 250,000 Syriacs were slaughtered by Ottoman Turks during World War One.

Far greater numbers of Armenian Christians were also killed during that war in what both groups call genocide.

"Sometimes it seems as if it's one long, unending war," Bandak says. "We are like skeletons passing through this land." (Editing by Peter Graff)