In 1978, Hardy took the part of the irascible but good-natured Siegfried Farnon in All Creatures Great and Small, the long-running BBC series based on James Herriot's best-selling books.
As the senior vet of the small Yorkshire Dales practice, Robert Hardy became one of the best-known faces on British television.
Full of animals, nostalgia and rural scenery, the show became a massive hit, attracting audiences of up to 20 million.
The original run ended in 1978 but the series was revived ten years later after the BBC obtained permission to write new storylines, having exhausted the original James Herriot books.
But the new scripts failed to meet with Hardy's approval and he rewrote large parts of his dialogue. "All they did was make Siegfried explode and be bad-tempered. I kept changing things."
Hardy cornered the market in the role of blustering aristocrat, often dressed in tweed.
He appeared in The Far Pavilions, The Cleopatras, Bramwell and Middlemarch, and on the big screen in The Shooting Party and Sense and Sensibility.
He explained: "When you've lived a goodish span as I have, it's a case of roaming round the attic and borrowing a few characters."
Laird
Despite this range, Robert Hardy's own volatility and ability to express his wrath were channelled most successfully into his many portrayals of Britain's most revered premier.
He played Winston Churchill six times in all, even once in French on stage in Paris, but most memorably in the 1981 mini-series The Wilderness Years.
Hardy said himself of his complete immersion into the character, "My family complained loudly about my behaviour while I was playing him."
He was married twice and had three children. Awarded a CBE in 1981 for his services to acting, Hardy was also a keen student of military history and supported the project to raise the Mary Rose.
In 1995, he gave up his long-time home in Oxfordshire, to become laird of a Scottish mansion, a 13th century miniature castle situated near Edinburgh, complete with a walled garden and 50-foot tower.
The actor had visited the place as a child, and sworn always to return, following in the footsteps of a previous visitor, Sir Walter Scott, one of Hardy's personal heroes.
In later years, he suffered from cancer of the colon, but recovered to resume as busy a career as ever, including film work.
Although he failed to make the lasting impact on Hollywood enjoyed by some British actors, his face became known the world over when he appeared as the Minister of Magic, Cornelius Fudge in several of the Harry Potter films.
He was dropped from the role after the studio balked at paying a £1 million life insurance premium which was demanded because of his advancing age.
RIP...