Orga was born in Istanbul in 1908 into a prosperous family of the old Turkey under the sultans. His mother, married at 13, was very beautiful, a quiet, loving young woman who seldom left the house - and never unveiled - but sat doing her embroidery in the company of her formidable mother- in-law, who lived with them. His father ran a carpet business. The household was happy, full of affection and humour. His uncle and aunt had a farm where the children spent their summers.
Then came the 1914 war. Orga's father was sent to Gallipoli, leaving behind him two small sons and a baby daughter. He never came back; nor did his brother. What remained of the family fortune went up in flames during one of the periodic fires that destroyed many of Istanbul's old wooden houses. By 1916, Orga's mother, aged 22, was penniless, with three children to bring up.
Though she and her mother-in-law argued, though the children were often hungry, though the boys were sent away to a bleak military school, she kept the family alive by sewing in a factory and later by her embroidery. But at great cost: the gentle figure of Orga's childhood became remote, eventually sinking into madness, and ending her life in a mental hospital.
Orga, by then an officer in the Turkish airforce, came to England to fly Spitfires with the RAF in 1941, and it is here that the Portrait ends. We know of his later life from his son, who wrote an afterword for the Eland edition. After Orga took up with an Irish girl, he was never able to return to Turkey, where military officers were prosecuted if they married foreign women. He lived by writing books on modern Turkey, on Ataturk and on Turkish cooking.
But he never learnt to speak fluent English - though he writes it with precision and grace - and never found much of a life. He died, a depressed and solitary figure, at 62.
Portrait of a Turkish Family is almost unbearably sad. After many years of joylessness, estranged from the mother whose love he had sought so hard to hold, Orga writes about remembered happiness, a time of lost love.
His talent lies not only in the simplicity of his narrative, but in his remarkable ability to pick out a scene with delicacy and clarity. The images are those of a child, later interpreted with the understanding of an adult. Reading it again, I still think that Portrait of a Turkish Family is one of the great memoirs of the 20th century.
Caroline Moorehead's `Human Cargo: a journey among refugees' is published by Chatto & Windus, pounds 12.99Reuse content