The Big Read: Past is a fogged mirror

Susanna sits, flanked by her grandchildren at the edge of the fading family portrait. Her face is vague, the imprecise chemistry of the photograph eroding her features into mere hints of a thin, tight mouth, of wary eyes.

But then you look away, back to the men. It is they who draw the eye in this picture, with their dark whiskers and theatrical, faintly melodramatic, poses: the picture was taken in the early 1920s, but the mood is Victorian. In this tableau, Susanna is easy to pass over; a woman just barely caught on film, slowly being rendered invisible by her age and by the vigour and beauty of the young people around her.

The photograph is a scene of carefully constructed domesticity but also of permanence.

Three generations sit together, their unity claiming not only the past but also the future. This family, the picture seems to declare, has always been, and will always be. If history is a river, then these are the occupants of the First Class lounge in a mighty modern steamer.

And yet Susanna would have known, as she posed and whispered to my grandfather to stop fidgeting, that rivers can narrow, dividing into tributaries, becoming shallow, dwindling to a trickle, a single drop ...

Twenty years before she sat surrounded by her clan, Susanna was in a British internment camp in the eastern Orange Free State with her two daughters.

The girls, in their early teens, were the last of Susanna's eleven children. Most had died before the war, not surviving their first year, but the camp had probably claimed at least one.

Perhaps it was a determination not to bury the last of her children that made her desperate and resourceful. Perhaps an Englishman simply left a gate open. Whatever the circumstances, one day Susanna took her girls and walked out of the camp and kept on walking, up into the foothills of the Maluti mountains and finally up into their lonely heights, to get as far from the British as possible.

They were found by a Basotho clan, and taken before the chief. I imagine him sitting in his royal seat, trying to hide his anxiety that the whites and the war were suddenly so much closer than he had hoped; weighing up his responsibilities as a chief, as a host, perhaps as a Christian, or as a Basotho facing a Boer woman with the wars of dispossession still in living memory.

He could have sent her away, or traded her to the British for some small patronage, or worse. Instead, he offered her protection. In return, she and her daughters would be his washerwomen. And that is how my grandfather's grandmother spent the last months of the Boer War: washing a Sotho chief's laundry, not with hurt pride or indignant pouting but with quiet gratitude.

Susanna and her walk up into the mountains are part of my heritage. I look more closely at the old photograph, seeing hidden strength in those hooded eyes. I look across to the soft, pretty face of her daughter, my great-grandmother, and search it for signs of that extraordinary childhood experience. I have visited the eastern Free State where Susanna farmed, and I have looked up into the mountains which saved her life, and to which I therefore owe my existence.

But this story makes me sad, because there is another face that wasn't photographed. Two people saved my family, and I only know the name of one of them. Susanna had the will to live, but the Basotho chief had the humanity to keep her life-force safe. Three generations of my family owe an immense debt of gratitude to that man and yet here, as we celebrate our heritage and are urged to find our common South African-ness, I feel the gaping distance between us. The saviour and the saved, two gentle people, have been pulled apart by time and politics, and here I am, left with a debt unpaid, a heritage only half understood.

Every day we pose in the carefully framed photographs of our own lives, hoping to convey some sense of history stretching away behind us and destiny stretching ahead. It is easy to be seduced by artifice. The idea of heritage encourages us to believe in a form of manifest destiny, to feel that we are where and who we are because a long line of forward-thinking ancestors has willed it to be so. It makes us think that we are demigods, that we don't need the mortals around us.

But, in the afterglow of this week's holiday, it might be worth reflecting that many of us are here not because our ancestors were great or mighty or rich or cunning, but because they were weak and lost. And, when they were at their most helpless, they received kindness instead of apathy, and were accepted when they might have been turned away.