Castle worth fighting over ... yours for a cool £15m

Seton Castle, near Longniddry, has been targeted by a leading American estate agents, which believes the 18th century property will smash all previous records.

Coldwell Banker is expected to begin a massive marketing campaign next week, which will include advertising the stately home in a special brochure designed exclusively for US billionaires. The property is likely to appeal to super-rich Americans and could attract corporate presidents, politicians or even Hollywood stars.

The huge price tag will limit the number of prospective owners to just a small handful, and it will dwarf the current record price for a home in Scotland - 2.34m for a house in Murrayfield.

Seton Castle, which was designed by renowned architect Robert Adam in 1789 and built from the ruins of Seton Palace, has 14 bedrooms and approximately 20 acres of land - and has been completely refurbished over the last 18 months.

The current owner, Mary McMillan, bought the castle for 1.3m in December 2003 when it was in a dilapidated state. She has since overseen a complete overhaul of the stately home with the help of family friends who donated hours of service for free.

The 43-year-old mother-of-six today, who would not reveal how much had been spent on the refurbishment, said she would be reluctant to leave her home but explained that she could not turn down a multi-million pound offer.

"I remember walking down the drive when the castle was up for sale and I fell in love with it - I knew that I had to buy it, even though it was in a dreadful state," she said. "The walls were crumbling and there was a musty smell throughout the building. The lawns were completely overgrown, but I could see the potential.

"It’s been a whirlwind renovation programme, which is now almost complete. I used the very best people in Scotland to create my home and so many of them offered their time for free because this castle is part of Scotland’s heritage.

"A short while ago, I invited a rep from Coldwell Banker to have a look at the place and they told me it would sell for $28m.

"There’s just no way I could say no to that kind of money, so I agreed to let them advertise it. They have set up a huge marketing campaign, which will start before Christmas.

"Estate agents usually plan for a 12-month campaign, but they are so certain the house will sell that they have signed up for a six-month contract. A lot of interest from America is expected."

Mrs McMillan admitted eyebrows were raised when she purchased the castle, as she comes from a working-class background. She was brought up by her mother in a Loanhead miner’s cottage, her father died when she was just eight, and she left Lasswade High at 16.

Through "buying and selling" items as diverse as furniture and property she developed a healthy bank-balance and later married husband David, now a retired property developer. Despite living apart since 1995, he remained involved in the restoration project.

Three of her daughters - 11-year-old Velvet, Mercedes, eight, and Porsche, three - now attend Scotland’s oldest private school, Loretto, while her other three children are all grown up. John, who is the oldest at 26, now lives in an annexed cottage in the west wing of Seton Castle, while the family’s butler also lives in the home.

Mrs McMillan sold her Brunstane home for over 1m in 2002, which enabled her to purchase the castle. The castle’s previous owner, the Earl of Wemyss, had put the house on the market for the first ever time - inviting offers over 750,000.

Mrs McMillan explained: "There were over 70 offers, 20 of them serious, and those were whittled down to two, mine being one. I had to sweat because I was given 16 days to come up with the cash.

"I also had to convince the earl, who’s in his 90s, that I was really serious - not only with my initial offer of well over 1m, but also that I’d lovingly look after the house and be responsible for gradual restoration where needed.

"I promised I’d give it every respect. He was genuinely delighted that Seton Castle was going to function as a family home."

Mrs McMillan began the refurbishment last spring, which included rebuilding brickwork in the courtyard, and transforming the dark and dingy cellar into a basement - complete with kitchen, billiard room, wine cellar, and a playroom for the children which is Mrs McMillan’s favourite room.

The open spaces in the house are all painted red, while each room has a unique silk wallpaper design. On the ground floor, the house has a large reception hall, as well as a drawing room, dining room, morning room, and butler’s pantry. Upstairs, the first-floor contains a 440 square feet master bedroom, a hall, two smaller bedrooms and a dressing room. On the second floor, there are three en-suite bedrooms, a library, a study, gallery, and two more guest rooms.

All of the interior decorating, which is different in each room, was completed by Malcolm Duffin. As one of Scotland’s top interior designers working for Whytock & Reid, Mr Duffin also designed fabrics and furnishings for the royal family, before the 199-year-old Edinburgh company went into liquidation earlier this year.

Mrs McMillan said she was "forever grateful" to Mr Duffin and all the other workers who had spent 18 months refurbishing the castle.

In particular, she praised cabinetmaker Michael Hart, artist Rachel Bell, plumber Tom Knight, Thomas Maxwell of Maxwell Flowers and painter Mark Hunter.

Although there is still some textile work to be completed at the castle, Mrs McMillan said she was "absolutely delighted" with the finished product.

"I love every part of the house and I don’t think a refurbishment like this could be repeated. If I do sell, I know that I will have to stay in East Lothian - I couldn’t move too far away from Seton Castle."

Palace was poisoned chalice

THE site of Seton Castle, nine miles south east of Edinburgh, is next to that of the historic Seton Palace, a vast courtyard house originally built in the 1100s.

The Seton family who lived there are considered one of the most illustrious of the great houses of Scotland. The clan was founded by Seier de Seton, who was granted lands in East Lothian to which he gave his own name. His family married into powerful alliances and his descendant, Sir Christopher Seton, married Christian Bruce - sister of Robert the Bruce.

He was later executed for that support, so King Robert enlarged the existing Seton lands by confiscating the property of English supporters - soon a large stretch of the East Lothian coastline became Seton territory.

Towards the end of the 15th century, the fourth Lord Seton endowed a collegiate church, which stands just yards from Seton Castle and is now looked after by Historic Scotland.

George, the seventh Lord Seton, was a close friend to Mary Stuart, Queen of Scots. The queen spent time at the home of the Seton family following the murder of her second husband, Lord Darnley - the couple also spent their honeymoon there.

As supporters of the Stuart dynasty, the family took to the Jacobite cause and their lands and titles were forfeited after the 1715 rebellion.

Seton Palace endured much rebuilding over the centuries, often being destroyed because of its proximity to the main invasion route from England. By the 1780s, it was a ruin.

But its stones were used by Robert Adam when he was commissioned to design Seton Castle in the summer of 1789. The new owner, Lieutenant-Colonel Alexander Mackenzie, was in his early 20s when he had commissioned Adam.

But he would not live long to enjoy his new house. According to a local tradition he evicted an old woman who lived in a cottage on the estate near Seton Palace. She laid a curse on him and prophesied that the new Seton Castle would never become his family home. He died five years later in 1796.