You don’t choose your parents and they didn’t choose theirs. I never met Charles Royds, my maternal grandfather, who died when my mother was a child. What remains of him is memorabilia from the defining years of his life – from 1901 to 1904 – when, at the age of twenty-five, he was first lieutenant on Captain Scott’s first Antarctic expedition.

As a child I became familiar with his tales of exhaustion, frostbite, cramp and snow blindness from his journals and sledging diaries. I was fascinated by his wooden goggles with narrow cross-like slits – still lying on my desk – which failed to prevent his eyes streaming with frozen tears as the sun stabbed his eyes, while he and his team dragged heavy sledges for up to a hundred miles – comparatively easy when the weather was good and the terrain flat, but, in storms, racked by the wind and crippled by cracking ice crust, their progress became a blind stumble.

When I look down a stairwell I feel mild vertigo, yet I never tire of the mystery of why men should push their bodies to exhaustion and beyond and then go back for more. ‘Because it’s there.’ Is there any answer less adequate than this and is there any more sufficient? I admire what I am unable to do, and my grandfather’s descriptions of camping in blizzards made me whimper with vicarious dread. Pitching his tent, he thrashes against the gale like a drunk, fumbles sightlessly for poles, pegs and groundsheet. Once inside he gets cramp in his legs while he changes into his dry clothes. As he takes off his mitts to undo leggings that have become pipes of ice, his fingers grow numb and inflexible. He takes hay from inside his ski boots and puts it in his shirt to keep warm for the morning, and puts on his human hair night-socks. His pipe is frozen, his matches are damp, his tobacco is sodden and, even though he’s kept it under his shirt, his flask of water is frozen solid. He wraps himself in fur, climbs into his sleeping bag, longs for something to eat besides biscuit and, as summer night seeps seamlessly into summer day, he’s too cold and too exhausted to sleep.

Back at base, when he reads an earlier account of an Antarctic expedition, he spits indignantly at the descriptions of brooding over loneliness, weeping over sweethearts and being too tired to cut one’s hair. He doesn’t present himself or his colleagues as men without fear or without a sense of danger. For him, the wonder – if there is wonder – is in their ordinariness:

-63°F What I call pretty chilly!!! One can’t help laughing when one thinks of a sore throat and cold in England and thinking how one doesn’t dare show one’s nose out of doors . . . The winter cannot be all joy and comfort, & no one could expect it, but with the help of a little self-denial, a little tact and a cheery face most of the monotony and discomfort can be overcome. We shall act like ordinary human beings.

I marvel at this. Is it courage? Is it stoicism? Is it wilful lack of imagination? Through the inverted telescope of history I try to parse his meaning. For him being ‘ordinary’ meant a belief in duty and service, in moderation, mutual respect and self-control. It meant a determination not to whine, to whinge or to exaggerate one’s suffering – in short the characteristics of an exemplary English Edwardian gentleman, frequently encountered in fiction and rarely observed in life.

Distinctions of rank and class were intrinsic to those beliefs: my grandfather had been an officer since the age of thirteen. But, if I’m to believe his journals, during the three years of the expedition he shared living accommodation, sledging duties and danger with others without any class distinctions. Complaints about his companions were reserved for his commander, Scott. A typical entry: ‘Had a row about last night’s fire (some Dundee jute had spontaneously combusted) . . . I expected to be blamed for it and was not disappointed.’