'We slept rough and battled wild animals to restore a Welsh castle'

Peter Welford and his wife Judy Corbett remember clearly the first night they spent at Gwydir, the 14th-century castle they own in Wales.

The couple slept on a mattress made from bubble wrap – they owned hardly a stick of furniture – while, around them, water gushed through the roof into buckets. They'd already had to evacuate the horses and chickens that had been roaming free in one of the wings, while another wing in the near-derelict stone building had taken a battering of a different kind, having been unofficially used as a venue for huge rave parties. Outside, the once-magnificent formal Tudor gardens had succumbed to years of neglect and were "a complete wilderness", with vast 300-plus year-old Cedar of Lebanon trees – planted as a commemoration of the marriage of Charles I and Henrietta Maria – towering darkly above the tangle of foliage below.

And, everywhere, the history of the place was tangible. Former residents had: fought at the battles of Poitiers, in 1356, and Agincourt in 1415; been a cousin of Queen Elizabeth I; had associations with the Gunpowder plot; employed Sir Charles Barry, the 19th century architect of the Houses of Parliament. There were also rumours of grisly goings-on over the centuries – Gwydir is said to be the most haunted house in Wales.

Incredibly, Corbett was just 26 and her then husband-to-be, Peter, only a few years older when they moved in, in 1994, leaving behind their lives in London, where they had worked, respectively, as a trainee antiquarian bookbinder and art historian.

They hadn't set out to buy a castle. Suddenly the enormity of what they'd taken on began to hit home. The pair had bought, on a massive mortgage, a home that needed hundreds of thousands of pounds worth of work done to it before it was even habitable. They also had the added responsibility that Gwydir is a Grade-I listed property – so all work would have to be done in accordance with strict regulations. As for furnishing it – well, they weren't going to be able make do with a few items from Ikea.

"Our friends and family thought we were completely mad," Corbett admits. "And had we been older, we probably wouldn't have done it. We'd have thought about it too much."

"We'd been looking for a house to restore for a few years, something that hadn't been compromised architecturally," Corbett says. "A cottage would have done...."

Instead, they fell for Gwydir.

"We literally happened upon it one day and jumped over the gate," she says, "a wonderful iconic image of the derelict country house." The couple had been visiting north Wales, where Corbett is originally from. She'd recalled the place from her childhood, when it had been open to the public. "I remembered the peacocks. They're a big part of Gwydir."

Having been sold by the retired bank manager who'd owned and restored it in the 1940s, the castle – technically classed as a Tudor courtyard house – had changed hands "half a dozen" times in quick succession since the Eighties, and was, in theory, then being looked after by a caretaker – the one who hosted raves in it. "That it was in such a state was probably why we fell in love with it in the first place," Corbett says. "It was the romance of it; it was like Bluebeard's castle – covered in creeper, you could hardly see it and there was this very overgrown garden. The place just sort of captured our imaginations, really."

The couple was also worried no one else would protect the property – not even the authorities. "There was talk of planning application to build chalets on the law," Corbett says with a shudder. "We were so concerned about its future and thought we could save it." There was something of a rude awakening when the sheer scale of what lay ahead became clear.

"Getting up on a Monday morning with no money, in a house that was leaking, was a bit daunting," Corbett admits. Especially when they suffered with terrible chilblains because the place was so cold. And one morning, they discovered the gardens "almost completely underwater" due to a tendency to flooding (something that continues to be a challenge).

Slowly, they began to break down the jobs at hand into manageable chunks. "There were some fairly obvious things, collapses in the chimneys and facades – so our first job was to make it wind and watertight." Perhaps surprisingly, Corbett says they think their lack of funds has been a bonus in the restoration. "We've patched," she says. "There's been maximum historical retention because everything we could keep we've kept. Too much money in the wrong hands can be a very bad thing for the restoration of a house."

And before they'd even started, they were positive about the restrictions that Gwydir's Grade I listing would bring. "We never wanted to put double glazing in the windows, never wanted to try to impose a modern life on the house."

Because the house can be so cold, they spend a lot of time in the library – a cosy, wood-panelled and teal-painted room stuffed with books and furnished with chairs draped in blankets, a small fireplace and gilt-framed ancient portraits.

Another favourite room – though less warm – is the Hall of Meredith. With its ancient timbered roof and huge open stone fireplace it looks uncannily like a location set from The Tudors – and daily domesticity continues there.

As for the chilblains, a heating system has been one concession to the 21st century, particularly because one wing of the house now provides bed and breakfast, so must conform to a certain level of comfort. But you'd be hard pushed to see it – pipes have been carefully disguised and radiators hidden behind panels in the walls. Much of the furniture has come from auctions – they recently procured a fireback installed by Sir John Wynn (b. 1553), whose regal Welsh family dominated the early history of Gwydir.

They are still on the long quest to reinstate every original fitting and piece of furniture they can lay their hands on. Many of Gwydir's innards were sold off in 1921, and soon after the couple moved in, neighbours came over with the original sale brochure. They have been working their way through ever since.

One of the most unlikely returns is the 1640-built dining room. The entire interior – including door frames, wall panels, leather friezes, window shutters and carved fireplace – was bought in the 1921 sale by William Randolph Hearst (the paper magnate who inspired Orson Wells' 1941 film, Citizen Kane) for wholesale transplantation into his extraordinary mock-ancient castle at San Simeon, in California. But Hearst died before he was able to install the room and it was bequeathed to the Metropolitan Museum of Art in New York. With substantial detective work, Corbett and Welford tracked it down and negotiated – aided by financial support from CADW, the Welsh historic environment service – to buy it back (£35,000, plus £16,000 for shipping). In 1998 Prince Charles officially opened the restored room. Sadly, it was only one of two entire rooms that Hearst had bought. The other was the Oak or Breakfast Parlour (it dates back to 1580) and the couple is currently "obsessing" over its location, which continues to elude them.

The castle, says Corbett, "gives you a tremendous sense of your own mortality. We're just caretakers in a chain." She is very interested in the "strong" wives and the women of the house, particularly Katheryn of Berain, also known as Mother of Wales (b.1534). The descendent of Henry VIII married four times and her third husband was Morris Wynn, father of John. It is said that she poured molten lead into each husband's ears in order to kill him and allow her to remarry. "It rather sends a shiver down my spine when I touch door handles that I know she touched," Corbett says. Does she ever feel scared? "Not now. This is a very happy house... but we did have some very strange times here at the beginning. People do say that when you're doing restoration work you can disturb spirits, or whatever you want to call them, and certainly something happened that did make us question what we were doing."

In Castles in the Air, the book she wrote several years ago about the restoration of Gwydir, she recounts that strange period: "It started with the builder's tools. A drill lying on the floor suddenly starting up and spinning around in circles; then the CD player flaring up into life at full volume. And strangest of all, my engagement ring vanished for over a week and suddenly reappeared one morning in the bathroom sink. There was a subtle shift in the atmosphere of the house – an edge, you might say..." Corbett began to sense a woman, whom she would later describe in detail and name as Margaret.

The couple was each aware of strange happenings, but didn't dare discuss them for fear of "imbuing the shadows with life". That is, until Welford was nearly killed by a spade falling from the roof. In the hospital, as he recovered (with 10 stitches to the head), they finally shared their experiences. On hearing his fiancee's description of the presence she'd sensed and glimpsed, Welford said it fitted a character he'd read about in ancient Wynn family manuscripts: Lady Margaret Cave, Sir John Wynn's wife, whose turbulent relationship with her husband had ended with him fleeing abroad and leaving her, bitter and frustrated, in the house. Corbett had not, until this point, mentioned that she already had come to the name Margaret by herself. Once they'd worked it all out, she says, the strange atmosphere went away.

Ghosts, of course, are just one of the more challenging things about living at Gwydir. Records show that in John Wynn's day, there were 60 servants to run the place. "Now there's just us with a bit of help," Corbett says. Does she ever look at more modern, less complicated houses in interiors magazines with envy?

She pauses. "No. We are utterly obsessed with this house. Every day is a wonder at Gwydir. We're very lucky to be here."

Castles in the Air is published by Ebury (£8.99). To order a copy for the special price of £7.99 (free P&P) call Independent Books Direct on 08430 600 030, or visit www.independentbooksdirect.co.uk