Christianity is not a Western religion. It was not founded in London, however much the Victorians liked to believe that God was an Englishman, nor in Rome, still less so in Brussels. It was born in Jerusalem and received its intellectual superstructure in the great cities of the Eastern Mediterranean: Antioch (modern Antakya in Turkey), Damascus, Constantinople (modern Istanbul) and Alexandria.

What is true of the religion as a whole is especially true of its sacred music. There is firm documentary evidence that the oldest Western plainchant, that of the Church of Milan, was deliberately modelled on older Syrian practice: St Ambrose’s biographer writes that the hymns and psalms of the church of Milan ‘should be sung in the Syrian manner’ because it was so popular. This is certainly the case: there are references in the sources to bands of Syrian monks bursting into song in Haghia Sophia, astounding the Sunday congregation with their strange litanies to the crucified Christ.

Moreover the greatest of all Byzantine composers, the appropriately named St Romanos the Melodist, was a Syrian from Emesa, modern Homs, just to the south of Aleppo. His hymns and antiphons took Justinian’s Constantinople by storm, but they have been shown to be heavily indebted to those of St Ephrem of Edessa. Furthermore, St Hilary of Poitiers who first introduced the hymn to Europe likewise drew heavily on St Ephrem’s

Edessan hymns for his models – he seems to have first heard the new form when he was exiled from Gaul to Asia Minor by the Emperor Constantius. St Ephrem’s work, in turn, has affinities with certain types of very ancient Jewish synagogue chants, particularly those preserved by the Jews of the Yemen. The Eastern tradition of sacred music, in other words, takes us back to the deepest roots of Christian tradition.

These traditions have been maintained for centuries in the fortress-like monasteries of the Eastern churches, and by the Great Orthodox monastic tradition which aims at the purification of the soul through the taming of the flesh, where the material world is pulled aside like a great heavy curtain to allow man’s gaze to go straight to God. The monasteries where this spiritual warfare took place were spaces that preserved everything that had been salvaged from the wreck of classical civilisation, and so preserved the learning of antiquity from the encroaching barbarism.

It was from the Eastern Mediterranean that Christianity spread first to Armenia, Persia, India, Byzantium, Ethiopia and Russia, and only much later to Western and Northern Europe. At the Council of Nicea, where the Christian Creed was thrashed out in 325AD, there were more bishops from India and Armenia than there were from Britain, France, Spain and Germany put together.

Ethiopia, or the Axumite Kingdom, became Christian as early as the fourth century and retained a strong connection up until the 20th century to the Coptic church. Its scriptural language is Ge’ez and it has a distinctive iconographic, liturgical and musical traditions. Sixth-century St Yared is still revered as the lodestone of Ethiopian music. During the 9th and 10th centuries, Christianity also spread from Byzantium into the Balkans and eventually into Kievan Rus, leading to the establishment of the Russian Orthodox Church. Russian Orthodox choral singing has roots in Byzantine music but imbibed western harmonic influences especially from the time of Peter the Great at the turn of the 18th century.

In what were once the homelands of Christianity, its great tradition of art, music and spirituality is in mortal danger. The slow and still continuing unravelling of the vast multi-ethnic multi-religious diversity of the Ottoman Empire has been the principle political fact of both the Middle East and the Balkans ever since the mid-19th century. Under the capricious thumb of the Ottoman sultans, the different faiths, tribes and ethnicities of the Ottoman empire had lived, if not in complete harmony, then at least in a kind of pluralist equilibrium: an interwoven patchwork of different communities living separately, yet side by side. But with the Ottoman retreat from the Balkans in the early 19th century, and the eventual collapse of the rest of that empire in the aftermath of the First World War, that patchwork was ripped completely apart.

Everywhere, pluralism was replaced with a ferocious polarisation. Almost all the former Ottoman lands suffered bouts of savage bloodletting, and some of these, most recently in Syria from 2011, grew into civil wars of startling violence fought along religious fault lines.In the aftermath of each of these wars, from Sarajevo to Baghdad, in dribs and drabs, and occasional tragic exoduses such as occurred with the Mosul Christians last summer, ethnic and religious minorities have fled to places where they can  be majorities: the Pontic and Smyrna Greeks to Greece; the Anatolian Armenians to Armenia; the various Jewish communities to Israel, in each case creating religious nationalisms operating in two directions. Those too few for that, such as the Chaldean Christians have tended to abandon the region altogether, seeking out places less heavy with history, such as North America or Australia. The recent Islamic State-driven exodus of the Christians of Hassake and Palmyra is only the latest chapter in a process that began with the secession of Serbia and Greece from Ottoman control in the 19th century, and the subsequent explusion of their Turkish minorities: in 1878, for example, about 130,000 Bosnia Muslims migrated from Sarajevo to areas under Ottoman control.

Islam has traditionally been tolerant of minorities: the relatively privileged treatment of Christians under Muslim rule contrasts strongly with the fate of Jews and Muslims in, say, 15th-century Spain, forced to flee or convert and even then pursued by the cruelties and tortures of the Inquisition. As M de la Motraye, a 17th-century Huguenot exile escaping religious persecution in Europe admiringly  put it, ‘there is no country on earth where the exercise of all religions is more free and less subject to being troubled, than in Turkey’. The same broad tolerance that gave homes to the Jews expelled from Spain and Portugal also protected Eastern Christians.

All this came to an abrupt end after the First World War, and the establishment of a series ethno-religious Ottoman successor states like Serbia, Turkey and Israel. Here citizenship was often conflated with a religious and ethnic identity. In each of these, majoritarianism was the rule, and minorities felt increasingly unloved and unwelcome.

Today, almost everywhere, those great exoduses continue. In Egypt, the succession of revolutions and counter-revolutions have been accompanied by a series of anti-Coptic riots, killings and church burnings. In Gaza and on the West Bank, the Palestinian Christians are emigrating en masse as they find themselves uncomfortably caught between Netanyahu’s aggressively pro-Settler government and their increasingly radicalised Sunni neighbours.

In Syria, most of the violence has been along the Sunni-Alawite fault line, but there have been a growing number of reports of rape and murder directed at the Christian minority, who used to make up around ten percent of the population. Many have already fled for camps in Lebanon, Turkey or Jordan. There are tragic reports of the wholesale emigration of the ancient Armenian community of Aleppo to Yerevan.

The worst affected areas of Syria are of course those controlled by the Islamic State (ISIS). Last summer, ISIS issued a decree offering the dwindling Christian population of eastern Syria and northern Iraq three options: either convert to Islam, pay a special religious levy – jizya – or be killed. If they did not comply, ‘there is nothing to give them but the sword’. The passing of the 20th July bloody conflict led to possibly the largest exodus of Middle Eastern Christians since the Armenian massacres during  the First World War, as the entire Christian community of Mosul headed off towards Kirkuk and the relative religious tolerance of the Kurdish zone of Iraq.

Even before this latest exodus, at least two-thirds of the Iraqi Christians had already fled the country in the after the fall of Saddam in 2001. The Christians were concentrated in Mosul, Basra and especially Baghdad, which before the US invasion had the largest Christian population in the Middle East. Although the 750,000 Christians only made up about seven percent of the pre-war population, they were a prosperous minority under the Baathists, as symbolised by the high profile of Tariq Aziz, Saddam’s Christian Foreign Minister, who used to disarm visiting foreign dignitaries by breaking into ‘Onwards Christian Soldiers’ in Aramaic, the language of Jesus.

According to tradition it was St Thomas and his cousin Addai who brought Christianity to Iraq in the first century. The region became a refuge for those persecuted by the Orthodox Byzantines, like the Church of the East that brought the philosophy of Aristotle and Plato, as well as Greek science, medicine and music, to the Islamic world, and hence, via Cordoba, to the new universities of mediaeval Europe.

St Thomas is also supposed to have visited India. In modern Kerala there still live a people who believe that St Thomas came to India from Palestine after the Resurrection, and that he baptised their ancestors. This is not a modern tradition: it has been the firm conviction of the Christians here since at least the sixth century, and probably for centuries before that. Although the historicity of the legend is ultimately unprovable, the modern St Thomas Christians, as they still call themselves, regard this tradition as something more than a myth: for them it is an article of faith which underpins not only their religious beliefs but their whole identity and their place in Indian society. Moreover they are agreed – as, amazingly, are many of their Hindu neighbours – that St Thomas is not dead: that he is still present in Kerala, guarding over his followers and guiding his church.

Like the Christians in the Middle East, the Christians of India are living in uncertain times. Just over a decade ago, in 1999, a wave of anti-Christian violence over the border in India led to the burning down of more than 40 churches in the Dangs region of Gujerat. Social boycotts were organised against all Christian converts, and the pressure led to an estimated 2,500 reconversions back to Hinduism out of a regional Christian population of between 20-30,000. There have been more church burnings this year, and India’s Hindu nationalist prime minister has called for ‘a national debate on conversions’.

Some blame insensitive American missionaries who enrage Hindus. The National Missionary Movement of India, based in Tennessee, talks on its website of how ‘Satan has successfully camouflaged his grip on the people with a thin veneer of religion’. This sort of activity brings despair to established Indian churches. Similarly it was American foreign policy that made life impossible for many of the Arab Christians. Now, almost everywhere, Eastern Christians are leaving in the wake of the upheavals that followed 2001’s ill-judged Anglo-American adventures intended to suppress terrorism. According to the historian, Professor Kamal Salibi, this leaves the Arab world vulnerable: ‘Each time a Christian goes, no other Christian comes to fill his place,’ he told me when I went to see him in Beirut a few years ago. ‘If the Christian Arabs continue to emigrate, the Arabs will be in a much more difficult position to defend the Arab world against Islamism’.

Certainly since the 19th century, the Eastern Christians have played a vital role in defining a secular Arab cultural identity. It is no coincidence that most of the founders of secular Arab nationalism were men like Michel Aflaq, the Greek Orthodox Christian from Damascus who founded the Ba’ath Party in the 1940s, along with other Syrian students freshly returned from the Sorbonne, or Faris al-Khury, Syria’s only Christian Prime Minister. If ISIS manages to turn itself into a permanent, Christian-free Jihadistan, it may well represent the death knell not just of the Arab Christians but also of the secular Arab nationalism the Arab Christians helped create.

Despite sizeable Christian populations remaining in Lebanon, Jordan and Egypt, there is likely to be little place for Christian Arabs in a Middle East rebuilt on the intolerant Islamist ideology of ISIS. Instead, their future is more likely to resemble that of the most influential Christian Arab intellectual of our day, Edward Said. Born in Jerusalem at the height of Arab nationalism in 1935, Said died far from the turmoil of the Middle East in New York in 2003. His last collection of essays was appropriately entitled: Reflections On Exile. If this happens, only in Greece, Serbia, Bulgaria, Russia, Kerala, and Ethiopia are there likely to remain large Orthodox communities still intact in their homelands.

Hence the timely importance of Sacred Imaginations: New and Ancient Music of the Christian East. Not only does it demonstrate the incredible strength of this music and its potential for reinvention and innovation, it also showcases some superb artists drawing on traditions of great power and importance which are, in some places, under threat.

© William Dalrymple