During the twilight years of the Ottoman empire at the end of the 19th century, as ethnic tensions flare between the groups that inhabit its vast territories, a young boy flees a massacre and finds shelter in Aleppo with a wealthy Muslim family. Like his hosts, Hanna is part of the empire’s wealthy elite. Unlike them, he’s a Christian. Almost immediately, he becomes best friends with Zakariya, the son of his protectors. Over the next 70 years, Hanna and Zakariya’s friendship will be tested by every conceivable challenge: war, flood, ethnic conflict, intolerance, extremism, famine and the tensions between their religious faiths. Hanna and Zakariya’s youth and early manhood are spent entirely in pursuit of pleasure. They carouse in the red light district of Aleppo, have a memorable encounter with one of the city’s most notable courtesans, run away to Europe and spend time in Venice. On their return, they commission a friend, a Jewish architect, to build them a pleasure palace on the outskirts of the city. They call this the “citadel”. It’s part brothel and part casino – a kind of Ottoman Animal House where anything goes and they can drink, gamble and sleep with prostitutes. There’s even a special room set aside in which gamblers who have lost everything can kill themselves. (Luckily or not, it never appears to be used.) Marriage barely dents Hanna and Zakariya’s playboy lifestyles. Instead of being repelled by their husbands’ licentiousness, their wives find the men’s single-minded pursuit of personal freedom commendable. Zakariya spends his time as a breeder of pedigree horses; Hanna earns a good living from his family estates. But this phase of their lives – carefree, thoughtless, somewhat exploitative – comes to an abrupt end when a cataclysmic flood sweeps away a village, drowning dozens of people, including Hanna’s wife and young child. Hanna and Zakariya’s response to this tragedy is what will shape the second half of their lives. Hedonism gives way to grief, a religious awakening, and an increasingly tragic understanding of the world. No One Prayed Over Their Graves is a vast, sprawling saga that depicts, among other things, the birth pangs of modern Syria. By and large, the action unfolds in its second city, Aleppo. Born in the outskirts of the city himself, Khaled Khalifa enthusiastically portrays Aleppo’s beauty, chaos, cosmopolitanism and licentiousness. The city he presents to the reader is ripe with possibilities for freedom, reinvention, friendship and illicit love. Few of his characters are bound by a single identity: they’re complex, contradictory and changeable. The novel’s humanist credo is summed up by Zakariya’s sister, Souad: “What she was doing harmed no one, it was merely another way of understanding life.” It will escape few readers that, since the beginning of the Syrian civil war in 2011, the millennia-old city that Khalifa describes so lovingly has been bombed out of all recognition. The events the novel covers – from roughly 1880 to around 1950 – are a mirror of Syria’s more recent calamities. Ultimately, it feels like a desperate act of remembrance, an attempt to retrieve and celebrate Aleppo’s lost past. While the flood is the midpoint of Hanna and Zakariya’s lives, dividing their world into before and after, it’s actually described on the first page of the novel. Khalifa eschews a chronological telling of his story in favour of one that flits between different periods. One of the challenges of the book – and something that is characteristic of his other fiction – is the density of the exposition, the sheer number of minor characters, and the reluctance to settle within any single character’s point of view for more than a paragraph. To make things even more complicated, the largely third-person, omniscient narrative is broken up with other fictional forms: first-person reflections by Hanna, and a section about a doomed love affair between a Christian man and a young Muslim woman that is presented as a self-contained short novel by a man called Junaid Khalifa. Leri Price, who translated three of Khalifa’s previous novels, does a fine job reflecting these different modes. However, there’s no doubt that the complexity of the book’s form, the restlessness of its narrative voice and welter of detail are taxing. The reader has to work pretty hard to make out the larger shape and purpose of the novel. Oddly, given that Khalifa is also a screenwriter, there are relatively few scenes in the book and almost no dialogue. Much of the book is pure chronicle, told in a diegetic prose that is as unstintingly curious about the details of such minor figures as say, Teodor, a Dutch photographer who’s enthusiastic about the Russian Revolution, as it is about the characters who are more central to the narrative. One of the controlling ideas of the book is the importance of living one’s own life and refusing to conform to any expectations, whether they’re imposed by family, or religion; societal or aesthetic norms. This attitude is reflected in the life of the author himself, who chose a career as a writer at 15 and has continued to reside in Damascus throughout the current war, when there are doubtless safer and more comfortable havens available to him. It’s commendable, I think, that the book is also clear-eyed about the tragic price of such choices. Readers who persist will be rewarded by a series of moving revelations. A love affair that has twinkled on the margins of the story suddenly reveals itself; Hanna recognises that his friendship with Zakariya has itself come at a terrible price; and an almost unbearably sad act of commemoration takes place over the book’s final pages. As the title implies, the novel sets out to be a vast act of remembrance. Steeped in more recent tragedies, superbly even-handed in its sympathies, it takes on the burden of granting all of its characters the blessing of a final prayer. No One Prayed Over Their Graves by Khaled Khalifa, translated by Leri Price, is published by Faber (£14.99). To support the Guardian and Observer, order your copy at guardianbookshop.com