Lord Montagu, who established the National Motor Museum at Beaulieu, has died aged 88.
A spokeswoman for Beaulieu Estate, in the New Forest, said Edward, 3rd Baron Montagu of Beaulieu, died "peacefully" after a short illness.
He is survived by his wife Fiona, his son and heir Ralph, daughter Mary and second son Jonathan.
The Hampshire estate and visitor attractions are to continue to operate as usual, the spokeswoman confirmed.
An estate funeral will be held at Beaulieu, followed by a memorial service at St Margaret's in Westminster "for his friends in London and further afield", she added.
The dates are yet to be confirmed.
Lord Montagu was one of the pioneers of the stately home industry and first opened his home, Palace House, to the public in 1952.
He also founded the National Motor Museum on the 7,000-acre (2,800-hectare) estate and was a leading authority on veteran and vintage cars, usually taking part in the London to Brighton run.
At the age of two, Lord Montagu succeeded his father, John, to become the 3rd Baron.
He studied at Eton and then Oxford, after army service as a lieutenant in the Grenadier Guards.
In 1948, when he was still in the army, he made his maiden speech in the House of Lords.
Lord Montagu was involved in two infamous trials.
At the first in 1953, he was cleared of a serious offence against a 14-year-old boy scout.
However, the following year the peer was charged with homosexual acts, which were then illegal.
He pleaded not guilty but was convicted and given a 12-month jail sentence.
An obituary on the Beaulieu website said Lord Montagu went about rebuilding his life and developing the estate following his release from prison.
"While not wanting to hide his bisexuality, he was also determined to keep his private life private and refused to comment on the events of the trial, a silence broken only in 2002 with the publication of his autobiography Wheels within Wheels," it said.
Lord Motagu became the first chairman of English Heritage, the Historic Buildings and Monuments Commission, in 1983 and served until 1992.
He fought vigorously - though often unsuccessfully - to have various buildings listed.
Lord Montagu took over the running of the Beaulieu Estate on his 25th birthday in 1951.
It had previously been managed by his mother and the trustees since the death of his motor pioneering father in 1929.
He later described it as a "white elephant" after finding the £1,500-a-year inheritance barely covered the running costs.
"The wise solution was to get rid of it," he said.
"For me, however - neither entirely sensible nor rational - that was unthinkable."
He later recounted: "What catapulted me permanently into the major league for the future was the idea of commemorating my father's life… by exhibiting veteran cars.
"Without it, my life would have been very different and I doubt whether I would have been able to remain as owner and occupier of my ancestral home."