Aladdin's cave of art goes under the hammer

Dozens of watercolours detailing the British landscape lined the walls, Old Master paintings were found hidden in chests and framed drawings were stacked in piles.

The lifelong professional dealer had a habit for keeping hold of paintings during his career and after his death, in November 2009, a hoard of more than 2,000 pieces worth close to 3m was unearthed.

No one had ever before witnessed the full extent of the collection, which was extraordinary for its range of styles, subjects and dates. Artworks from the Renaissance lay side by side with 19th-century topographical drawings; oil paintings of historical figures were found next to pencil sketches of South African harbours.

Those who sifted through the works in the modest Jersey farmhouse said it was incredible to see so many wonderful paintings in such a small space.

Now those artworks are being auctioned off by Christie's on behalf of his estate, the core bulk going under the hammer today, almost a year to the day of the collector's death aged 80.

And an atmospheric watercolour of Bolton Abbey, in the heart of the Yorkshire Dales, is one of the focal pieces up for sale in a collection named A Channel Island Treasure House.

Painted in 1800 by Thomas Girtin, a rival of JMW Turner, the work helped to establish watercolour as a reputable form of art. It is expected to fetch between 7,000 and 10,000.

"It is one of the most important paintings in the collection and the second most expensive work on paper," said the senior director at Christie's, Harriet Drummond.

"It's an absolutely wonderful landscape, this imposing ruin taken over by the landscape. It's a very romantic, very moody watercolour.

"Girtin loved the location and did seven versions of the watercolour, which is a lot, as well as four pencil sketches, so it was clearly important to him."

The only painting on paper worth more in the 328-lot auction is a panorama pencil drawing of Sheik Abd el-Qurna, Egypt, by Robert Hay, which measures more than three metres in length and has a guide price of up to 20,000.

But when the auctioneers first laid eyes on it in Mr Appleby's picture-strewn house, they could not be sure what it was.

"When we first went in there it was absolutely full to the rafters with paintings," said Mrs Drummond. "The painting just looked like a dirty scroll of paper but it has the most exquisite detail in it."

It is a scene the Appleby family were familiar with. John's daughter, Jane Appleby, said: "The house was full and it was a constant battle for my mother to stop him from covering every space with something,"

His son Richard Appleby, his added: "We couldn't move for tripping over pictures. It was the same with all his enthusiasms. Dad would overdo everything – in a nice way. He'd be very passionate and then onto the next thing, never do anything by halves. If you said you wanted some paint, there'd be tins and tins of it."

As the experts sifted through the huge assortment of works, they found paintings by Venetian masters Titian and Jacob Tintoretto, English Romantic John Constable, as well as five important paintings of Canadian landscapes.

At a couple of July auctions to sell some of the pricier artworks, a portrait of a gentleman by Titian sold for 289,250, an oil painting of a sleeping legionary by Ubaldo Gandolfi reached 373,250 and a view of Reading by Constable went for 181,250.

In September, the pieces which dealt with travel and exploration were put up for sale at two auctions. A pencil and watercolour scene of a shipping bay off the coast of Cape Town from 1840 fetched 1,250, while a 19th-century oil on canvas landscape of the Great Harbour in Newfoundland, Canada made 49,250

Mrs Drummond said that the lots going under the hammer today had been specially selected to appeal to art enthusiasts.

"This is the core volume of the collection," she said. "It is really interesting and accessible. There are lots of lots at 1,000 or less, yet you can buy very good drawings."

Mr Appleby came from a long line of art dealers but had not been actively trading works towards the end of his life. That goes some way to explaining why most of the pieces up for sale today have not been seen on the market in a generation.

Collector came from art family

Born in 1929, John Appleby came from a family of art dealers, his father and uncle having set up a gallery in London in 1922.

He moved to Jersey during the 1970s and traded as a dealer but his passion for collecting was recognised.

"John was acquisitive, it was terribly difficult to get him to part with anything," said one.

After Mr Appleby's death on November 2, 2009, Christie's auctioneers discovered his massive haul of fine artworks, which included the moody watercolour of Bolton Abbey by Thomas Girtin.

Girtin, who died aged 27, was influential in making watercolour a reputable form of art. JMW Turner, Girtin's contemporary and rival, once said: "If poor Tom had lived, I'd have starved."