When I was a gun-mad schoolboy of ten, one bitterly cold Christmas, camping in a rather seedy London mansion flat not long after the war, my father suddenly announced: ‘We’re going to live in Africa.’ My mother was appalled. I was absolutely delighted.

It was my godfather – a recently demobilised and dementedly optimistic Army major – who had given my father this bright idea a few days earlier, first of all proposing that they pool his army gratuity and my mother’s savings to buy ‘a stake in Africa’ and, when this financial notion failed to impress on the maternal side, going on to suggest that the two of them take up ‘positions’ (they neither of them, of course, ever took up ‘work’ or ‘jobs’) with the British Government’s recently introduced (and calamitously ill-fated) groundnuts scheme in Tanganyika.

‘They’re going to need people like you and me, Nat,’ my godfather said. ‘To get these groundnuts off the ground.’ There was a great deal of such vivid, arcane talk, I remember, throughout that freezing holiday of 1947 among these two very unagricultural men who had never been in Africa, about our coming life in the sun. We’d all be posted up to some Happy Valley, my godfather said, filling the dreary little chintz-filled drawing room with African romance, as he and my father ran imaginative riot through the dark continent, a safari whipped on by liberal whisky-sodas, while I listened spellbound.

‘Of course, the great thing will be the hunting.’ My godfather reached for the black-market scotch he’d brought with him. ‘All the animals – not touched since before the war. Bound to be thick on the ground. There for the taking….’

He took another large measure. ‘I still have my old Mauser. And I fancy, Nat, you would very soon pick up the knack again out there.’ The knack he referred to was my father’s pre-war habit of moving round the Dublin cocktail bars with a loaded .45 under his coat, where he had once blasted the tops off the brandy and Benedictine bottles in the Wicklow Hotel – target practice before moving on to the real thing in the Spanish Civil War, a campaign luckily frustrated when the plane he was piloting never made it beyond Biarritz, and he and the rest of his bibulous Irish Brigade spent a week at the Imperial Palace instead, ambushing the champagne, before flying back to Dublin.

But I knew nothing of this at the time. All I heard then was the talk of guns. There were going to be guns in my coming life, real guns, not toys: Winchester .375s for the lion and a hand-tooled Purdey .450 Express for the elephant. I couldn’t believe my luck. I’d be in Africa by the summer, freed from my wretched prep school – in Africa, stalking the animals – and more: an expedition up from the steamy coast, across the cool blue plainslands, over the great lakes; and then the darker journey into the interior, through the dripping rain forests, towards the Mountains of the Moon, before a long and difficult voyage on the Congo river, down the far side of Africa, in native pirogues….

Of course, I knew Africa in those days, even if my father and godfather didn’t. During longer holidays with cousins in a large Victorian house in Ireland I had read all the classic texts: some bound copies of the Boys’ Own Paper and the rest of an Edwardian adventure library, once the pride of an even more distant relative, where I had unearthed the dusty, empire-glorying books, from attics and playroom shelves, cleaning the covers, the gaudy coloured pictorial boards with their Union Jacks and blood-red images of derring-do – so that the young lieutenant’s scarlet tunic, white pouch-belt, pith helmet, and lanyard on the front of Captain Brereton’s With Wolseley to Kumasi – A Tale of the First Ashanti War came to shine mint fresh, as the intrepid officer pushed his way through an evil mangrove swamp, service revolver at the ready.

Before that cold winter holiday in London I had travelled the blistering Somali deserts with the same Captain Brereton, seeking revenge against the lesser breeds in The Grip of the Mullah. I had been in search of Prester John, too; risen over the animal-choked plains of east Africa with Jules Verne for six weeks in his balloon – and journeyed with him to the centre of the African earth. Above all I had gone with Allan Quatermain to King Solomon’s Mines – and Gagool the Witchfinder was never really dead for me. She lurked, half-crushed, yet still half-alive, in the broom cupboard at the bottom of the back stairs, or more certainly in the old laundry on the way to the yard where there was a malign Victorian device – a thundering linen press that worked on rollers, pressed down by a moving coffin-like half-ton weight – a mangle that had caught the witch in its huge rolling jaws but had not quite extinguished her evil flame.

In the morning room of this old house there were other more exact, supposedly factual African accounts, which I sought out and browsed through during the long, rain-sodden Irish days: bound, late nineteenth-century copies of the Sphere and the Illustrated London News – which made Africa blaze and spark more than the crackling fire, where the artists, suggesting even colour by the stark and detailed horrors that they concentrated into their line engravings, brought the blood of Africa right onto the morning-room carpet for me – that dark, savage continent that the Victorians always wanted to see it as, so that they could save it with all sorts of missionary and military endeavour. For them, in their high-minded libraries and studies, Africa was a relaxation, a fantastic, long running adventure serial – as it became for me, sixty years later, a child thumbing through the same illustrated magazines.

Here, in the final desperate defence of Khartoum, I saw the Mahdi’s troops advancing on General Gordon standing on the Residency steps with a bible in his hand – and later his decapitated head which the wicked infidels flourished aloft on a spear. Poor, brave General Gordon. I felt like Queen Victoria. I had a defective Diana air rifle in those days and there was a clump of bamboo to one side of the house – the nearest approach, I thought, to rampant African conditions which our mild Irish climate allowed. If the rain stopped before lunch I would go there with my rifle, push through the dripping greenery and exact a terrible vengeance on all the mad mullahs.

In those days, even the cold, dark granite church on the edge of the estate I made over into one of Livingstone’s baking equatorial mission huts. And in place of the interminable hymns, prayers, lessons, sermons and squeaky harmonium music I set up a faith in the African rite, so that the sounds of that low church on its rain-streaked, northern hill were replaced by hot murmurs, savage words and music: tribal chants, war cries, tom-toms, black magic at the altar – with the chance, when the collection plate came round, of making a conciliatory peace offering. Though this was rare, for the black man in me was angry then. And it was Livingstone himself, rather than mild-mannered Canon Bradshaw, who spoke from the pulpit – confronting an unruly, unchristian mob, where Aunt Susan and Uncle Harold over from Bagshot had gone native and were getting restless, only waiting my command to attack the Canon for his long-windedness, transfixing him with the assegais I had conveniently to hand in the shape of the dripping, steel-tipped umbrellas and walking sticks left in the church porch.

Above all, I knew from these adventure books, Africa had a certain haunting, unmistakable smell: a sweet smell of decay – decayed vegetable – and of leprous flesh, too: a mix of burnt cow dung and exotically perfumed flowers as I understood it. So that one summer, out on the yard manure heap, I set fire to a dead crow and some rotting turnips, the funeral pyre covered with June rose petals stolen from the pleasure garden. The resulting odour was thrillingly unspeakable.

I grew up with Africa on my mind, if not in my veins. For me it was a place of pulsating, ultimate adventure, of liberating space and freedom from the confines of a restricted, almost Victorian childhood: a world of dos and don’ts, of nannies, governesses and tears-before-bedtime – which I had to invent every sort of release from, so that when my bedroom candle went out, I spoke to myself in a variety of imagined African tongues, heroic dialogues, full of wet labials, snorts and strangled gutturals – the routine secrets of childhood normally shared, but here turned in on myself and transformed into heated native debates. Sometimes the darkness of my bedroom ideally mimicked an impenetrable African night; or, when the rain fell outside my window, the patter on the Virginia creeper was the happy sound of a torrent in a tropic forest. At other times the walls and ceilings dissolved, giving way to starlight on the plainslands, infinite space where the lion roared. Here, before sleep, round the fire of my mind – the sheets monkey skins, the eiderdown well tucked up as a zebra shield beneath my chin – here in the warbling speech of equatorial river tribes, I planned battles against rival clans and surprise attacks against the white man. In these nights I gathered around me, like toys or teddy bears, all the loose fictions of a boy’s Africa – witch doctor’s masks, long barbed assegais, poisoned arrows, old black powder Martini-Henry rifles – which I then...