Sir Nicholas Mander and his wife Karin talk to John Hudson as they open their home, Owlpen Manor, to the public for another season

A nother May comes around and another visitor season for Owlpen Manor, which manages to be known by large numbers of people in the South Cotswolds and beyond, yet still has the unworldly air of a remote and beautiful place from a bygone age.

Its situation partly accounts for that, in an amphitheatre of a valley, one of the deepest and most secluded on the Cotswold Edge, with just the west side open to the Severn Vale.

It's been praised by a who's who of arty visitors over the years, but the iconic gardener Gertrude Jekyll said it all on the eve of World War I when she wrote: "Among little hillside gardens treated in a formal fashion, none is more delightful than that of Owlpen Manor... with what modesty the house nestles against the hillside and seeks to hide itself amidst regiments of yews."

A lot of visitors describe the house as "small" or "tiny", which is an interesting glimpse into the mind-set of those who can regard a 10-bedroom property as such.

But yes, as a house to visit, it is endearingly compact, and equally attractive to lovers of medieval buildings and admirers of the Arts and Crafts movement of a century ago.

Above all, Owlpen is unashamedly a family home, and the lucky family is that of Sir Nicholas Mander and his wife Karin, who have been here since 1974.

They have five grown-up children, and all but one was born during their time here. As the visiting grandchildren multiply, there will probably come a time when the house will close to the public. But that's not this year, and we can enjoy it while we can, just as long as the weather behaves itself.

There's something about the house in Nicholas Mander, who turns 60 next year – quiet and understated but with hidden depths and a varied history. His family grew rich making paint, varnish and latterly printing ink in Wolverhampton, before the company was bought by an American conglomerate just over 10 years ago.

The Manders were big players in Staffordshire from Georgian times, as philanthropists and patrons of the arts as well as major employers, but it was not until 1911 that a baronetcy came the way of Charles Tertius Mander in George V's coronation honours list.

Sir Nicholas is the fourth baronet, but educated at Downside and Cambridge, his career has not been in varnish and ink. He was co-founder of Mander Portman Woodward, one of the country's best-known independent sixth-form college groups, and has been a director of property development companies in London and Spain. More locally, he helped Alan Sutton get his publishing company going in Gloucester back in the Seventies, and is deeply involved in a variety of charities and amenity organisations.

Houses and estates evolve; Owlpen, like a lot of its fellow tourist attractions in this part of the world, has seen its visitor numbers dropping off in recent years, but there are other ways ahead.

"When we came here in 1974, the farm was a relatively serious component of the estate," says Sir Nicholas. "Now it's of no relevance at all and it's just a question of maintaining it. A lot of smaller houses like ours are going more towards weddings and corporate events, and that's what we're doing, in a small way.

"We're not licensed for weddings – Stroud District Council, with which we have an excellent relationship in general, was worried they would generate too much traffic round these little lanes. But we're ideal for receptions for up to about 80 people, with our restaurant and room for a marquee.

"Our holiday cottages are also something we've developed. When we came here we had the nucleus of the manorial estate – redundant staff cottages, an old grist mill and barn, which in the 18th century was known as the cider house, and the court house, where the court leet was held.

"All of them were crumbing to pieces but now they have a new life and a future, as well as bringing in income for us. We restored them as nine cottages at the rate of about one a year, between 1975 and 1985, since when it's been a case of upgrading kitchens and bathrooms.

"Just as my wife and I came here as a young couple, had our children here and now see them coming back with children of their own, some of our holiday cottage clients are people who came as children, kept coming as young marrieds and are now back with grandchildren. Some people say Owlpen is timeless, but really, you see life flying through the place."

The restaurant's success owes much to Sir Nicholas's Swedish-born wife Karin, who also takes a keen interest in the garden. He says his own approach to gardening lies more in planning and design, but for years his pride and joy, until he found that a man with mechanical clippers could do the job at least as well and in a fraction of the time, was the meticulous hand-clipping of the towering yew trees planted close to the house.

"They were very much out of scale and out of shape when we arrived," he says. "They had been planted as a 'yew parlour', but they were more like a wilderness. You have to be more brutal with them than you think to get them back in order. Some of my friends thought I was a complete butcher and the trees would never recover."

Those yews mean a lot to the Manders. They dominate an etching of Owlpen by the Cotswold Arts and Crafts artist FL Griggs, and the couple had a pleasing sense of life imitating art as the trees were gradually sculpted back into shape.

The reclaiming of the rest of the garden was just as tricky. "At first, I did quite a lot of visiting Italian and Renaissance gardens," says Sir Nicholas. "Then I contacted the garden designer Sir Geoffrey Jellicoe, and he replied that the great thing about Owlpen is that its so un-Italian – it's got this great medieval sense of organic growth.

"Then again, we've read in books that we have this wonderful Arts and Crafts garden designed by Norman Jewson. In fact, he didn't do any gardening at all; it's our garden.

"Jewson bought the house in 1925 as a labour of love and kept it for a year, in which time he repaired it after 100 years of dereliction. But he had no time for the garden.

"Happily, we got to know him in his old age, when we first came here. The house was sold for the first time in 1,000 years when he bought it, he sold it at a loss a year later and it's had three owners since then."

It's a house that dates from 1450-1616, with a magnificent Tudor great hall, a Jacobean parlour wing dated 1616 and an elegant early Georgian little parlour, remodelled in 1719 among its finest features. The great chamber contains unique painted cloth wall-hangings dating from about 1700, about which Sir Nicholas plans to write a book aimed at arts professionals. He has also written a family history, with another in the pipeline, as well as the Country Houses of the Cotswolds book reviewed here.

Oh yes, and the ghost. There's got to be one of those, hasn't there? At Owlpen it's Queen Margaret of Anjou, the wife of Henry VI, who stayed here in early May 1471 on her way to disaster at the Battle of Tewkesbury. She is said to keep returning to the house where she spent her last happy night before her defeat, exile and widowhood.

Sir Nicholas has never had the pleasure of meeting her, but reckons some people pick up the vibes. "A film crew turned up from the television programme Most Haunted," he muses. "The presenter was a great actor..."

Owlpen Manor, near Uley, is open until September 30, on Tuesdays, Thursdays and Sundays but not Bank Holiday Mondays. The restaurant and gardens are open from noon to 5pm and the house from 2pm to 5pm, last admission 4.30pm. Admission is £5.75, children aged four to 14 £2.75, family £15.50; entry to the gardens and grounds only is £3.75, children £1.75.

Country Houses

Sir Nicholas Mander spoke to scores of friends and fellow country house owners to compile Country Houses of the Cotswolds (Aurum Press, £25). He also drew upon some 200 photographs published in Country Life over the past century – a unique repository of architectural history.

The result is a splendid coffee-table book in which more than 30 houses, grouped by period and style, reveal the historical and architectural importance of the Cotswolds.

They range from sublime castles such as Sudeley to early manor houses, among them Owlpen Manor, Daneway House and Snowshill Manor, and then there are the important Jacobean manors, including Stanway and Chastleton.

The second part of the book focuses on the great classical country houses and noblemen's palaces of the 18th century, notably Badminton House and Dyrham Park. And the third section surveys the 20th century and beyond, not least such Arts and Crafts showpieces as Ernest Barnsley's Rodmarton Manor and William Morris's Kelmscott.

What all these houses have in common is an ambience and presence that make them unforgettable to all who know them.