It was Johnny Dumfries’s good fortune to be born into the Scottish aristocracy, as a descendant of Robert the Bruce and the heir to the marquisate of Bute. It was his bad luck, when his career as a grand prix driver appeared to be taking off, to be chosen to partner Ayrton Senna in the Lotus team during the 1986 season.
The young Brazilian, already recognised as Formula One’s outstanding new talent, was adamant that all the team’s efforts needed to be concentrated into supporting the No 1 driver, meaning himself. The man in the second car was effectively there to make up the numbers.
And so it proved. While Senna won two grands prix that year, the Earl of Dumfries could do no better than a fifth place in Hungary. Discarded at the end of the season, he was never able to make his way back into F1, although in 1988 he achieved the distinction of becoming the first member of the British aristocracy to win the Le Mans 24 Hours race since Lord Selsdon in 1949.
Dumfries, who has died aged 62 after a short illness, retired from the circuits in 1991, leaving behind the memory of a likable, unpretentious man, talented enough to have made more of a mark. Two years later, on his father’s death, he became the 7th Marquess of Bute. Thereafter he devoted himself to the upkeep of the ancestral home, Mount Stuart, a Victorian gothic pile near Rothesay on the Isle of Bute.
He was born in Rothesay as John Crichton-Stuart, styled the Earl of Dumfries. His mother, Nicola (nee Weld-Forester), was the first wife of John Crichton-Stuart, the 6th Marquess, whose right to his title came by virtue of having been born five minutes before his twin brother. Educated at Ampleforth College in Yorkshire, the young Earl left before his O-levels – which he took at a London crammer – with the aim of pursuing his interest in motor sport. If there was no opposition from his family, neither was there financial support, and he earned his living as a painter and decorator and as a van driver for the Williams F1 team.
Undeterred by a karting accident in which he broke both ankles, he bought a Formula Ford single-seater and learned how to prepare it at a south London garage, working happily alongside other young men with similar ambitions. In 1983 he moved up to Formula Three, racing against Senna, who won the British championship before moving up to F1. The following year it was Dumfries’s turn to take the title, with 10 wins plus four more in the European series.
His exploits had brought him to the attention of various F1 team managers, and in 1985 he signed a contract with Ferrari to test a four-cylinder car built to the next set of F1 regulations. But when those rules were scrapped, so was his relationship with the Italian team.
Installed at Lotus but lacking experience with 1,000-horsepower turbocharged F1 cars, he soon discovered that an aloof Senna was being given the better equipment. By midsummer it had been made clear that there would be no second season with the team; as part of a deal to acquire Honda engines, his seat would go to a Japanese driver.
Unable to find another F1 drive, he moved on to the endurance racing circuit. In 1987 he set a new lap record at Le Mans in a Sauber-Mercedes. The following year he co-drove the winning Jaguar XJR9 with Jan Lammers and Andy Wallace, the marque’s first victory in the 24-hour classic since 1957.
Dropped by the Jaguar team after crashing while in the lead at the Nürburgring 1000km race later that season, he then spent two years with the Toyota endurance racing team before terminating his motor sport career when his father fell ill.
After succeeding to the title in 1993 he concentrated on making a go of the 3,000-acre estate. As chairman of the Mount Stuart Trust he turned disused farm cottages into holiday homes, revived the Bute Fabrics company, which had been founded by his grandfather, and opened the great house to the public.
Inspired by Goodwood’s Festival of Speed, he also inaugurated the Mount Stuart Classic, in which competition cars of all kinds raced through the grounds, although it lasted only two years.
He sold a second family mansion, Dumfries House in Ayrshire, to the Prince’s Foundation, a charity run by the Prince of Wales, in 2007. In December 2020 he and six other people, aged between 21 and 90, were charged with breaking Covid-19 travel rules after a journey from London, where he had a house in Ladbroke Grove, to Bute.
His first marriage, in 1984, to Carolyn Waddell, a former nanny, ended in divorce in 1993. In 1999 he married Serena Wendell, a fashion designer. He is survived by Serena and their daughter, Lola, by the three children of his first marriage, Caroline, Cathleen and John, and by two stepchildren, Jazzy and Joshua.