Just a few years back, Kenya’s Laikipia plateau was paradise.

Many times my wife and I have ridden out on horseback at sunrise among elephants and giraffe, buck, warthog and the occasional leopard, marvelling that such wild beauty still exists on earth.

No longer, however.

For many months now, Laikipia’s cattle farms and game ranches, many of them white-owned, have been invaded and overrun by armed tribesmen brandishing automatic rifles, burning buildings and terrorising owners as they claim grazing rights for their own cattle.

On Sunday, this scourge reached a new climax: the famous safari guide, farmer and former British Army officer, Tristan Voorspuy, was shot out of his saddle and killed as he inspected lodges on his estate that had been torched in an arson attack.

British born Father-of-two Tristan Voorspuy was shot dead in the region of Laikipia in Kenya

His death has sent a tremor of shock and outrage through white Kenya and its tourist industry, comparable with that in 2011 when Somali pirates struck at the country’s once-idyllic coast, kidnapping or killing several tourists.

For more than half a century since its independence in 1963, Kenya was considered a bastion of peace and stability amid the turmoil in much of Africa.

Yet in recent years, a plague of violence has spread, fuelled by land hunger among an exploding population, South Sudanese warlords, rhino-poachers and an increasingly corrupt Nairobi government.

Add to this an inflow of AK-47 automatic rifles, passed down from war-torn Somalia, which have fallen into the hands of thousands of north Kenyan tribesmen.

The Laikipia plateau is home to a band of mostly white farmers, left in possession of their land by successive Kenyan governments because it is relatively poor in quality. They ranch cattle, and, until recently, harboured a wonderful array of wild animals.

Fenced conservancies such as Mugie, Borana and Lewa, where Prince William and Prince Harry often stay, provide havens for rare species including Grevy’s zebra, white rhino and, above all, black rhino, which live under armed guard.

Mr Voorspuy was a South African-born British army veteran and was brave and tough in the way white settlers in Africa have always needed to be

Kenya’s Laikipia plateau is home to an array of beautiful wild animals from elephants and giraffe to the occasional leopard

But wire and wardens are no protection against the recent mass invasions by nomads hell-bent on seizing pasturage, indifferent to life or property, least of all that which is owned by whites.

They claim that drought is forcing them to seek new land for their cattle. The farmers suspect a political motive. In an election year when killers and poachers have votes, the government is doing little to restore order.

A month or so back, I received an anguished email from a farmer friend whose ranch we used to rent, telling of a guard shot dead at Mugie, of wholesale rustling and occupations. A Kenya farm website chronicles experiences of families who live in daily fear.

‘19 cows and 21 calves stolen yesterday in broad daylight,’ runs one extract, ‘well co-ordinated and planned which was trying to draw George [the farmer] and 5 officers into an ambush . . . Day 9 two of our staff beaten by a gang of 4 Samburu [a local tribe], one carrying an AK . . . Jamie Roberts came by plane to try to help . . . one shot fired at plane . . . There seems no end, and no political will to stop the slaughter of our national wildlife assets and also the destruction of private property.’

The murder of 60-year-old Mr Voorspuy will horrify every white in East Africa and the thousands of tourists who visited his 24,000 acre Sosian Game Ranch

Mr Voorspuy was killed when he went out to investigate fires started at lodges on his ranch

The game, glory of East Africa and jewel of the tourist industry, is being massacred for food, ivory and rhino horn. And the plains where such visitors as ourselves gazed upon a wealth of great animals, are today almost barren.

The gossip in Nairobi is that President Kenyatta cares not about tourists, only about power and bribes.

Yet as my wife says: ‘Who will go there, if there is no longer anything to marvel at?’

The murder of 60-year-old Tristan Voorspuy will horrify every white in East Africa and the thousands of tourists who took holidays with him and his wife Cindy at the 24,000 acre Sosian Game Ranch he co-owned.

South African born, for a time a Guards officer, he kept alive the old White Mischief tradition — both the good bits and bad. He rode hard and fast, partied likewise, and relished his remarkable power to seduce pretty women.

He was brave and tough in the way white settlers in Africa have always needed to be. If he had been more cautious — for instance, about riding out alone to investigate the damage to his lodges — he might be alive today. But men like Voorspuy know only one way to do things — and it does not involve backing away from danger.

Mr Voorspuy was known for riding hard and fast and relished his remarkable power to seduce pretty women

The tribesmen who murdered Tristan Voorspuy saw not a farmer whose life had been spent in Africa, but instead just a rich, white interloper on a horse who challenged them on land they demand to claim as their own

Pictured: The three lodges burned by armed tribesman who invaded Mr Voorspuy's Sosian Ranch in Laikipia

More than a dozen deaths in the region in recent months have been linked to tribesmen seeking new grazing for their herds, and following the death of Voorspuy, some 379 arrests have been reported.

What is happening in Kenya follows the grim pattern set in Zimbabwe by the monstrous Robert Mugabe, 93-year-old tyrant and mass murderer. Mugabe’s regime has evicted the white farming community and allowed a wilderness to replace some of the richest agriculture in Africa.

Now in South Africa, President Jacob Zuma is threatening the same policy, seeking to assuage the demands of an exploding population by appeasing land-grabbers, and appearing indifferent to the increasingly frequent murders of white landowners.

Zuma announced last week that his government is to conduct a ‘pre-colonial land audit’, to legitimise confiscation of property without compensation. One of his political opponents says: ‘He’s gone rogue on land reform.’

More than a dozen deaths in Laikipia in recent months have been linked to tribesmen seeking new grazing for their herds (Pictured, police arrive at Mr Voorspuy's Sosian ranch, following his murder)

Zuma says his purpose is to ‘reverse this historical injustice’ — the fact that 80 per cent of the country’s land remains in white ownership, while a quarter of the population is unemployed.

Like Mugabe a generation ago, South Africa’s leader seeks to whip up popular fervour for political advantage, when incompetence and corruption threaten to deprive him of power.

I have believed for years, through long experience of Africa, that the white man is doomed to be squeezed out of the continent — or, at least out of property ownership.

In 1994, when majority rule came to South Africa, I wrote from Cape Town that I did not believe the mere right to vote would satisfy the black population: they yearned also for the whites’ homes, cars, swimming pools, and would not rest until they got those things.

As for Kenya, my wife Penny and I have spent some of the happiest months of our lives on Laikipia, never tiring of such magic moments as the day we met a lioness while riding together.

‘I hope it’s not hungry,’ she said warily.

Like Mugabe a generation ago, South Africa’s leader Jacob Zuma seeks to whip up popular fervour for political advantage

‘Don’t be silly,’ I replied, perhaps with more conviction than I felt.

We and the beast stared motionless at each other for 30 seconds, at a distance of 30 yards, before it turned and loped away into the bush, leaving a memory that will never fade.

But that moment will not be repeated, and we tremble for the livelihoods of thousands of people, white and black alike, who are now threatened by an estimated 10,000 armed tribesmen, driving 135,000 cattle before them.

Law and order is a rare and precarious commodity. Few African governments acknowledge that without justice and the enforcement of property rights, no economy or society can prosper. Loyalty to tribe and family persistently trump rulers’ commitment to the welfare of their nations.

The tribesmen who murdered Tristan Voorspuy saw not a farmer whose life had been spent in Africa, and who provided employment for scores of local people, but instead just a rich, white interloper on a horse who challenged them on land they demand to claim as their own.

It is heartbreaking to see Kenya threatened with a descent into darkness.

Yet unless its government shows the will and means to restore peace to Laikipia, which means expelling this murderous throng of invaders by force of arms, the nation’s future stands at risk, and its priceless wild heritage faces the prospect of near-extinction.