WHEN STEVEN Campbell died suddenly last year of a ruptured appendix aged just 53 he left behind a reputation as one of the greatest Scottish artists of the last century.

He also left more than 30 unseen paintings and hundreds of drawings, populated by such dark and magical characters as Paisley crocodiles, baby-faced killers, and a youthful Captain Hook.

On the first anniversary of his death next month these final paintings will be displayed for the first time in a major new show at the Glasgow School of Art.

Called Wretched Stars, Insatiable Heaven, after a quote from Monteverdi's L'Orfeo, the exhibition features the paintings Campbell began working on in 2006 for a show at GSA. It was to be his first solo show in his old art school.

Kathy Chambers, the curator, called the event "a landmark exhibition" and one that will prove Campbell is one of Scotland's best artists since the Second World War.

"His legacy will grow and grow, we're absolutely sure of it," she said. "It's very exciting for people to see this new work. It's just unfortunate there won't be any more after these paintings.

"The themes he addresses are extremely poignant: mystery, danger and sudden death. The show takes place in the Mackintosh gallery. It was to be a homecoming for him as a painter."

His wife, Carol Campbell, said the new paintings are filled with the preoccupations of the last years of his life.

"He was doing what he always did - taking all his ideas and input from places he was visiting, conversations he had and mixing them up in that huge intellect that was his, and the poetry that was his, and bringing them out as Steven Campbell paintings," she said.

Certain themes run through and merge in his last work. Italian landscapes and small religious devotional paintings reoccur. Baby-faced killers stalk other canvases, with the artist watching on in the background. A French shape-shifting master criminal Campbell christened Bebette Nozieres lurks elsewhere.

But for Neil Mulholland, director of the centre for visual and cultural studies at the Edinburgh College of Art and Campbell's friend, the most haunting is the reappearance of a bottle of Gaviscon, the anti-heartburn medicine.

"He just thought he had acid indigestion, so he was eating a lot of it," said Mulholland. "But it was appendicitis. And they appear in a few of his paintings. They're ironic in a strange way. Maybe if he hadn't taken the Gaviscon he would have went to the doctors and been okay."

Campbell rose to prominence in the 1980s alongside fellow GSA graduates Peter Howson, Ken Currie and Stephen Conroy. Before starting GSA in 1978 Campbell was a steel worker for seven years.

In 1982 he travelled to New York to study at the Pratt Institute where he made a huge impact. New York-based poet and writer Barry Yourgrau said: "A lot of the work in New York at the time was really formalist and calculating, but Steven was part of a wave that boldly went bang. New York thought it was the centre of the world, but then these people from around the globe and Scotland showed up, it was like the barbarians invaded. It was thrilling."

His family hope that a major gallery will stage a large scale retrospective of Campbell's work. His paintings currently hang in the National Galleries of Scotland, Tate Britain in London, and MoMA in New York.

The date of the private view, August 15, will be the first anniversary of Campbell's death. Carol Campbell spike of why that date was chosen: "Do I sit in our house with my family, we all look at the empty chair at the end of the table, left just the way he left it? Or do I stand in a room filled with his paintings, filled with hopefully hundreds of people all talking about him and celebrating his life. Now, which option would you choose?"

The show opens on August 16.