The Earl of Rosebery and Midlothian, unconventional electrician who lit major exhibitions – obituary

The 7th Earl of Rosebery and 4th Earl of Midlothian, who has died aged 95, was a scientist, electrical engineer and agriculturalist with a brilliant, if unconventional, mind.

The grandson of Queen Victoria’s last Liberal prime minister, the 5th Earl of Rosebery, and Hannah Rothschild, he came to public notice in 1977, three years after succeeding his father, at the famous sale of Mentmore in Buckinghamshire, the spectacular Rothschild house which his father had inherited.

At the start of the auction the public address system failed. Not pausing, the youthful Lord Rosebery leapt into the rostrum, upstaging the chairman of Sotheby’s, Peter Wilson, delved into the wiring and fixed the problem in a trice.

The sad denouement of Mentmore, the most important of the Rothschild houses in the Vale of Aylesbury, was described as the “sale of the century”. It followed three years of fruitless negotiation with the Labour Government, to whom it had been offered with its collection for £3 million, in lieu of death duties, with the hope of it becoming a public museum.

As it transpired, the contents sale made well in excess of £6 million and the nation privately bought another million pounds worth of pictures and furniture. The Government’s mishandling of its acquisition was a turning point in the preservation movement in England, leading to the establishment of the National Heritage Memorial Fund and a happier outcome for many other historic buildings in the future.

Neil Rosebery’s unusual aptitude for science was perhaps a manifestation of a Rothschild gene, for his cousins included the scientist Victor (Lord) Rothschild and the world expert on fleas, Miriam Rothschild. As a boy he had a tin hut in which he built transistors, and at the Rosebery seat of Dalmeny, a Regency gothic house designed by William Wilkins overlooking the Firth of Forth near Edinburgh, he undertook rewiring until he got stuck under the floorboards, much to the irritation of his mother.

Neil Archibald Primrose was born in Mayfair on 11 February 1929 to his father’s second wife, Eva Bruce, daughter of the 2nd Lord Aberdare and former wife of Algernon Strutt, the 3rd Lord Belper. His father, the 6th Earl of Rosebery, was a first-class cricketer, the owner of two Derby winners, and a Liberal politician who was briefly installed by Churchill as Secretary of State for Scotland. 

Ronald, Lord Dalmeny, Neil’s elder half-brother by his father’s first marriage to Dorothy Grosvenor, died aged 21 in 1931, and Neil became the heir, taking the alternative courtesy title of Lord Primrose. 

He was effectively an only child. His half-sister Lady Helen Primrose was already 16 when he was born, and there were three adult Strutt half-siblings by his mother’s first marriage, including Lavinia, later Duchess of Norfolk. The young Neil occupied himself with his electrical enthusiasms and Meccano, and to the delight of his mother shared her passion for bridge. 

He was 11 when the Second World War broke out, and thanks to his parent’s friend, J Pierpont Morgan Jnr, was sent to the United States for two years, attending Millbrook School at Stanford, New York.

He was a contemporary of William Buckley, Jr, the writer who unkindly described him as an “uncontrollable brat”. Nevertheless, his scientific bent was nurtured there, and he developed pronounced lifelong characteristics, notably his unique diet of Spam, pizza, Mars bars, Pepsi Cola, orange cheese and steam-baked white bread, which harked back to his American war years.

On return to England, he broke with family tradition (his grandfather had asked for a record of the Eton Boating Song to be played at his death bed) and went to Stowe, where he continued to excel at science, taking the two-year exam in one.

After school he did National Service in the Royal Electrical and Mechanical Engineers – again a break with family tradition, of service in the Grenadiers – and then went up to Oxford to read physics at New College. There he developed an interest in stage lighting for the Oxford Union Dramatic Society, and after graduating in 1952 embarked on a career lighting plays, exhibitions and films.

In Edinburgh, where both his parents were involved in setting up the International Festival, he lit several events on the Fringe. In 1954 he was responsible for lighting the Diaghilev exhibition which made such an impression on the young Alan Bennett: “As a schoolboy in the drab world of the 1950s I remember being swept away by the glamour of it all.”

In London Neil worked for Strand Electrical, the leading stage, TV and film lighting company. He then founded his own lighting companies, On the Spot, and later, in Edinburgh, Northern Light. He was responsible for lighting the epochal 1961 Epstein Exhibition in Edinburgh, the 1964 Shakespeare Exhibition at Stratford and the Louis Osman exhibition at the Goldsmiths Hall in 1971.

Later in life he kept his hand in by designing spectacular lighting at Dalmeny for the Scottish reels parties on New Year’s Eve and electronically controlled firework displays from platforms in the waters of the Firth of Forth.

His career as a lighting professional coincided with marriage and the arrival of a large family, which gave Neil the secure emotional base he had lacked. He had met Deirdre Reid, an art student at the Ruskin, at the Oxford Playhouse, where he created the lighting and she painted the sets. They courted watching Marx Brothers’ films at the Walton Street cinema and married in 1955.

Deirdre Rosebery provided Neil with a strong centring force over the remarkable 70-year span of their marriage. Both were very strong characters. They had five children, four daughters and a son.

Married life was divided between a London house in Orme Square, and Dalmeny, where Neil became a progressive forester and farmer. The Scottish estates, the historic base of the family, were given to him by his father in 1955 and Neil and Deirdre converted the upper floor at Dalmeny into a self-contained family house.

After the sale of Mentmore the ground floor of Dalmeny was opened to the public after being rearranged to incorporate retained French furniture, Sèvres porcelain and paintings from the Rothschild collection in a series of tableaux-like rooms drawing on Neil’s experience of staging exhibitions and Deirdre’s interests in art. Neil would refer to her London museum friends as the “Art Department”.

The estates at Dalmeny and Rosebery became his passion. He planted five million trees – the woods in Dalmeny park are his memorial. A hands-on improver with a great eye for detail and an original approach to technical problems, he also restored cottages, rebuilt sea defences, converted farm buildings into new estate offices, restored Barnbougle Castle (his grandfather’s seaside library tower), designed grain driers, laid out a pioneering wind farm and built a biomass heating system, giving full range to his scientific bent.

He had a large in-house farming enterprise and could be found into his 80s driving farm machinery, diggers, and tractors very fast around the estate, chainsaw often to hand. When really bad weather set in he would be at his computer designing heating systems or checking the stock market on Ceefax. Still active in his 90s, he met his workforce every day at 8am and his hard work and attention to detail never faltered, to universal respect.

Neil was direct when he knew best and often silent when things outside his interests were discussed. One memorable occasion when this was not the case was when experts from the National Gallery visited Mentmore and informed him that they considered that the family Rembrandt was not authentic. 

Showing not the slightest emotion he simply asked them to put it in writing, quietly remarking that he knew nothing about art. His mother, who did, took the view that “experts always change their mind”. And so they did, when the Rembrandt Commission came to study the picture a decade or so later.

Lord Rosebery is survived by his wife and children. His son Harry Dalmeny, chairman of Sotheby’s UK, succeeds to the earldoms.

The 7th Earl of Rosebery and 4th Earl of Midlothian, born February 11 1929, died June 30 2024