One hundred years ago this month, a horse named Bomba romped home to win the Gold Cup at Ascot as his proud owner, James de Rothschild, looked on.

Born in France in 1878, James went to study at Cambridge University where he developed a passion for riding in point-to-points and hunts. He was a maverick and wiling to take risks, something that made him the subject of good-natured teasing.

But, aged just 20, he backed a horse named Jeddah at odds of 100-1 in the 1898 Epsom Derby. The horse made it first past the post and James’ reputation as a fearless gambler was born.

Much of his success on the racetrack was shared with trainer Frederick Pratt, whom he appointed in 1903 and remained personally and professionally attached to for 42 years.

The Epsom victory in 1909 forms the basis of a new exhibition at Waddesdon Manor celebrating the long and colourful horse racing heritage of the Rothschild dynasty.

The collection of archive photographs, letters and other documents reveals James to have been a fascinating character with a deep love of horses.

After finishing his degree, he was so keen to carry on with his equestrian activities, he wrote to his parents in Paris asking to stay on at university for an extra year.

But at the end of that time, he absconded to Australia in an attempt to experience life as an ordinary person, not a member of the rich and powerful Rothschild family.

There he spent 18 months, trying his hand at a variety of jobs, including working as a cowboy on a cattle ranch.

On his return, he dutifully took his turn in the bank, as was expected of all Rothschilds, but never lost his individuality, or his love of horses and racing.

During the First World War James was lucky to survive an explopsion which blew him out of his vehicle. After recovering from his injuries, he went back to France, continuing to contribute to the war effort as a courier on horseback.

Unfortunately, his horse was shot from under him and he was again seriously wounded, the result of which was to make him frail in later years.

The other major love of James’ life was his wife Dorothy, ne Pinto, who shared his interest in horses and racing. There are several photographs of her in the exhibition.

Waddesdon Manor’s own association with horse racing began after James inherited the estate from his aunt, Alice in 1922.

One of the first things he did was build a stud to house his brood mares and in fact it is still active and well-known in racing circles.

That same year, James was elected to the Jockey Club and the exhibition includes the original letter confirming his appointment.

On show are a couple of caricatures of him as he was a popular subject for the cartoonists on magazines Vanity Fair and Punch, due to his unconventional approach and that he was tall, gangly and wore a monocle. In fact, this was a legacy of an accident he had as a young man, when a golf ball hit him in the face and left him virtually blind in his right eye.

Curator of exhibitions at Waddesdon Manor, Diana Stone, said: “I have these visions of James and Dorothy sitting up late on winter’s evenings discussing which mares should be bred and what names to choose for the foals.”

Records prove that James had a sense of humour. When his horse Snow Leopard failed to achieve an expected win, he swiftly renamed him Slow Leopard.

Even when James was very old and frail, he and Dorothy would come down to Waddesdon every weekend, Diana revealed.

“James’ driver would take them down to the paddock and pull up as close to the fence as possible.

“He would whistle to call his favourite horse, Palestine and gave him treats,” she added.

After James died in 1957, Dorothy took over running the house in conjunction with the National Trust and kept the stud very much operational.

Her hands-on approach was evident in that she would arrive at Waddesdon on Friday evening and first thing the following morning would go to see the mares and foals.

Visitors to the exhibition can read archived records showing ledger books in Dorothy’s handwriting, relating to the birth and growth patterns of the foals.

There are also several hand-typed and signed letters from Dorothy to the racehorse authority, requesting specific names.

James was certainly not the first Rothschild to have a passion for horses and racing. Mayer Amschel Rothschild, from the London branch of the family, had a spectacular racing career.

In 1871, he won four out of five Classic races, while his nephew Leopold engaged in friendly rivalry with the Prince of Wales who was also an avid race-goer.

The French arm of the dynasty were also keen on the sport and bred and raced great stallions, including Brantome who won the French Triple Crown and the Arc de Triomphe.

The family’s association with horse racing is still strong and Waddesdon Stud continues to thrive, overseen by the present Lord Rothschild’s wife, Lady Serena Rothschild.

And in a splendid nod to the past, her horses still run in the same blue-and-gold colours as Bomba’s jockey sported when he took the Gold Cup a century ago.

The exhibition ‘The Rothschilds in Racing’ at Waddesdon Manor runs until November 1, 2009. To book tickets or for more information call 01296 653226 or visit www.waddesdon.org.uk