Imagine you have been walking up into the sky for four days on end, until you reach a frozen plateau as high as Mont Blanc. Only now does the serious business begin. Starting at midnight, you climb continuously for six hours in the dark up what seems like a near-vertical scree slope the height of Snowdon, at 20 degrees below zero while gasping for breath at 50 per cent oxygen. You have reached the crater rim of the highest free-standing mountain in the world, capped with cliffs of ice, only a few miles from the equator.
The map of Africa includes three physical features more familiar to Europeans than any other: at the top, the pyramids; at the bottom, Table Mountain; and between them that mighty volcano nearly 20,000 feet high whose name is best known from a short story by Hemingway which is not about the 'snows of Kilimanjaro' at all. I had three reasons for wishing to mark my 65th birthday by climbing it. I did not want to leave this life without attempting one serious world-class mountain. Now that my sons Nicholas and Alexander have reached their twenties, I wanted to complete their education by introducing them to the wonders of Africa. Finally, my mad friend Robin Page, the farmer and author to whom I was introduced years ago by Laurens van der Post, told me that climbing Kilimanjaro, twice, was the most enjoyable thing he had ever done and promised that, if I came along, he would organise a party to do it for the third and last time.
The physical preparation - weeks of cycling up and down the Mendip hills - was easy. The mental preparation, as what we had taken on loomed ever closer, was harder. A Somerset neighbour who had just driven round the base of Kilimanjaro kindly told me they had seen two corpses being brought down (it kills more people a year from altitude sickness than any other mountain in the world). Vaguely reassuring was a television documentary, Soap Stars Climb Kilimanjaro, showing six actors from Casualty and Coronation Street having a go (only two failed).
On a glorious September day the Booker team, including Nick's Polish girlfriend Anna, completed their training with a trot round the Brecon Beacons, then mugged up their tourist Swahili and joined the rest of Page's 16-strong party at Heathrow. Those bent low under backpacks included the couple who own the Cairngorms reindeer herd, several dedicated hill-runners bristling with fitness, and a qualified doctor. The Booker quartet, the only smokers, stubbed out their last cigarettes for a week.
From Nairobi, where we were met by our Kenyan leader, Anthony Cheffings, and two delightful Australian and Texan colleagues, we drove 100 miles south across the parched brown Kenyan countryside to Amboseli. For 24 hours we gazed at giraffes, lions, elephants, zebras, wildebeest and buffalo, while in the background the great mass of Kilimanjaro towered over the landscape, though still 40 miles away. After a last night in beds at Loitokitok, a ramshackle Tanzanian township of corrugated iron set amid little fields of coffee and bananas scratched from rich red volcanic soil, we gratefully handed over our backpacks to the team of 40 porters who would make it possible, and the game was on.
The four-day walk begins, in tropical heat, through dense jungle, full of white-faced colobus monkeys. After a few thousand feet this gives way to a strange moorland with heathers 30 feet high, then to a rocky landscape full of those yellow and silver everlasting plants sold in Christmas pots, where the only signs of birdlife are screeching ravens and little alpine chats, as friendly as English robins. Each day, soon after leaving camp, we would be overtaken by our porters, laden down with our equipment, who greeted us with cheery cries of 'jambo!' Each night, as we passed the height of Fujiyama, then the Matterhorn, was perceptibly colder. Ever clearer into view came the jagged pinnacles of Kilimanjaro's second peak, the virtually unclimbable Mawenzi, 17,000 feet high, and the now hugely swollen mass of Kibo, the chief summit itself. Long regarded by the local tribes as the unapproachable seat of God, it was first climbed in only 1889, when Tanganyika was still a German colony (its topmost point remained 'Kaiser Wilhelm Spitze' until 1964 when, in honour of Tanzania's new independence, it was renamed Uhuru Peak).
Finally, all vegetation and birdlife ceases and you emerge on to the silent stony plateau between the two peaks. The moment we had all been dreading for months was come. Two of our party were forced by altitude sickness to go down, including our doctor and my normally ebullient son Nick. At six in the evening we curled up, shivering, in our tents. Just before midnight we assembled in five layers of clothing. None of us, we agreed afterwards, had ever known anything like what followed, as we slogged hour after hour by torchlight up that frozen scree. Within an hour three more of the party, including two of the dedicated hill-runners, had been forced to give up. Finally, just when it seemed impossible to go on, after a last precipitous scramble up 100 feet of boulders, we stumbled on to a narrow rocky platform. Behind us the pinnacles of Mawenzi, eight miles off, were turning pink in the first rays of sun. To our right were the 100-foot-high ice cliffs of the summit plateau. As I was last to scramble up to the crater rim, behind Mr Page, I loudly complained that if he hadn't been so slow, I would have been up hours before.
After a brief, delirious pause, our admirable Kikuyu chief guide Joseph said that it was time to move on to the crater rim's highest point, a mile or two further on. When I saw that the first stage involved walking along a ledge hanging over a 150-foot drop, I decided that I had done enough to celebrate becoming an old-age pensioner. Two others agreed. It took the remaining eight of our party two more hours to battle on to Uhuru Peak, where Anna and Alex were first to touch the highest point in Africa. Only when, in the morning sunlight, we looked down the 3,000 feet of scree that we had climbed in the dark did we realise how mad we had been. I was so out of breath that long before I reached base camp I was overtaken by the first of our summiteers, floating down the scree as if on skis.
When we caught up with the invalids that afternoon, 4,000 feet further down, Nick was back to his irrepressible self. Having seen two inert forms being bounced at breakneck speed down the track on stretchers, possibly dead, he was relieved to see that his father was not one of them. The following afternoon, having strolled down 5,000 feet more through the forest, I asked for the porters to be assembled so that I could make a pretty speech of thanks on behalf of the group and present them with the tips that the custom of the mountain requires. For some reason this prompted Mr Page to compare me to my ancestor Bishop Patteson who, after piously addressing certain South Sea islanders in 1871, was placed by his hearers in a cooking pot.
The party then moved on to spend three relaxing days in the bush in Tsavo, with dinner served by lamplight in Mr Cheffings's dining-tent. The Booker family resumed smoking. We ended up with two even more luxurious days at Malindi on the Indian Ocean, where I was presented with a cake and serenaded with 'Happy Birthday' in Swahili. Amid scenes of rapturous accord in the local market I reached agreement with a crowd of stallholders that all politicians are corrupt, all lawyers parasites and all officials mad. As Kenya faces elections after 28 years of rule by Arap Moi, with his Kanu party in disarray, it seems that Private Eye's ancient joke, 'AprŒs Moi le dZluge', is at last about to come true. As we spent two hours at Nairobi airport watching a programme on the elections, the acerbic commentary from a cheerful Kikuyu lady behind the bar confirmed that politicians are no more loved in Kenya than in Britain. We were back in the real world.