Inside the mind of a power-crazed slum landlord with delusions of grandeur

The architect employed by Nicholas van Hoogstraten, convicted last week for the manslaughter of a business rival, tells James Morrison about his master's unhealthy obsessions

At 8am prompt he would rise from his four-poster bed, open his mail over a cup of tea and, after amusing himself briefly by humiliating a serf, repair to his study to ruminate over his empire. By 1pm, racked by migraine, he would be ready to lunch, then for seven more hours he would pore over his files before dining again at eight. Pausing only briefly to read the Financial Times and watch the TV news, he would work on into the night, retiring to bed at 3am.

For 20 years, this was the daily routine kept by "Mr N Hamilton", sometime alias of Nicholas van Hoogstraten, multi-millionaire property tycoon, would-be feudal baron and self-styled heir to Napoleon Bonaparte, Kubla Khan and the pharaohs.

Last week the slum landlord was exposed as a cold-hearted psychopath whose hired henchmen slew a business rival. Van Hoogstraten was convicted of manslaughter after his thugs stabbed 62-year-old Mohammed Raja in front of his grandsons and then blasted him in the face with a sawn-off shotgun.

A sequence of sketches, revealed for the first time by The Independent on Sunday, offer an illuminating insight into the mind of a supremely arrogant killer and the elaborate web he wove to keep his vassals in check. The drawings, labelled "A Typical Day for Mr N Hamilton (1985)", are the work of Anthony Browne, the architect of Hamilton Palace, the £20m monument to ego that Van Hoogstraten was having built near Uckfield, East Sussex.

Mr Browne, 41, who spent two decades supervising the construction of the incomplete palace, recalled Van Hoogstraten's "pharaonic delusions", and how he revelled in his diabolical reputation.

"He saw himself as a cross between a medieval baron, a paternalistic slave-master and a concentration camp commandant," he said. "He had the sort of attitude you'd expect from someone running a concentration camp who ends up allowing certain people to escape the gas chambers over a period of time, in exchange for their slavery and obedience.

"He had these pharaonic delusions. He was certainly very feudal, but he also had a neo-colonial bent, and loved the idea of the idealised relationship between a master and his loyal slaves. When I showed him my sequence of sketches, he loved it, including my depiction of him abusing a serf. He even wrote the word 'grapefruit' himself in pencil under the image referring to his breakfast."

Van Hoogstraten's sinister obsession with master-servant relations was most clearly symbolised for Mr Browne by his acquisition of a painting of Sally Forbes Bonetta, a six-year-old slave girl who was "gifted" to Queen Victoria by the King of Dahomey on the Gold Coast. He bought the watercolour at auction for £4,850 in 1986, and for several years afterwards it hung over his youngest son's cot.

To the hundreds who have suffered at Van Hoogstraten's hands, his cruelty is legendary. He famously dismisses his own tenants, many of whom have endured years of squalor and overcrowding at his hands, as "scum". And he reserves similar contempt for ramblers, whom he describes as "the great unwashed".

Last year, the Ramblers' Association won a landmark court ruling granting them access to a footpath bordering his vast Sussex estate. To this day, the path remains blocked by a shed and a discarded fridge.

Van Hoogstraten's most direct displays of aggression have had serious, if not fatal, consequences. In the 1960s, he was jailed for four years for a hand grenade attack on the home of a former business associate. Only last week, his former fiancee, 19-year-old Tanaka Sali, told how he grabbed her by the hair in a jealous rage and beat her with a slipper until it broke because he suspected she was dating another man.

Despite Van Hoogstraten's undoubted callousness, Mr Browne, for a long time one of his closest confidantes, confesses to having enjoyed his company. "I was his amanuensis most of the time, and towards the end I became more like the éminence grise," he said. "He lived in a lodge on the land where the palace was being built, and I was one of the few people who had close access to him.

"I did like him. He had a tremendous sense of humour, although admittedly it was of the gallows kind."

Of all the myths that surround Van Hoogstraten, Mr Browne is most amused by talk of his vast wealth. The tycoon has often boasted of his £500m-plus fortune, but his architect puts it closer to £40m. Neither was he greatly impressed by Van Hoogstraten's fabled artistic collection. Though it is reputed to include one of a handful of Holbein paintings in private hands, Mr Browne only ever saw a Jasper Johns and a Turner oil sketch of a sunset scarcely bigger than a postcard.

Moreover, he recalls Van Hoogstraten admitting on at least one occasion that he could not even remember which alias he had used to sequester certain assets, nor in which Swiss bank they now lay. He did, however, admire his antiques, notably a selection of French baroque pieces including a Louis XVI cabinet by Weisweiler, and his vast array of stamps and coins.

Mr Browne disclosed that, in addition to the sprawling Hamilton Palace, he had designed a near-identical mansion for Van Hoogstraten's estate in Zimbabwe. This too remains in a state of limbo.

He also revealed that Van Hoogstraten had secretly ordered his henchmen to "liquidate" all his assets, including the three hotels and 60 townhouses he owns around Brighton and his luxury homes in Cannes, Monte Carlo and Florida, should his appeal against his conviction fail. "He always said that, if he got convicted, he would liquidate the lot," he said. "He said people would just abuse it otherwise."

Of all Van Hoogstraten's possessions, Mr Browne believes Hamilton Palace, with its blend of English baroque and Venetian styles and its half-built mausoleum, is the most fitting monument to his downfall. "Its foundations are so deep, it would withstand a nuclear attack," he said. "But it will never be completed now."

He added morbidly: "We've been joking in my office that they should convert it into a secure mental unit. That way, if he really does want to move in when he eventually comes out, he can."

Of Van Hoogstraten himself, with whom he parted company two years ago over a dispute about the tycoon's increasing interference in his work, he concluded: "When he used to shout and bully people it was an act. But it only used to be. Once you start acting insane, before too long you become insane."