ONE of the least-known but most important collections of modern art in the UK has provided a new treasure for Scotland’s National Gallery.

The art works assembled by Royan Middleton, who ran a successful printing business in Aberdeen, have been described as one of the most fascinating collections of the modern era.

Now a 1885 pastel picture by Claude Monet, one of the works of art collected by Middleton, who lived from 1885 to 1965, has been acquired by the National Galleries of Scotland.

The Monet had been in the Middleton family since the 1920s but is now part of the Scottish national collections after being acquired under acceptance in lieu (AIL), a scheme run by the Government to offset tax.

Middleton had “discerning taste and vision”, Sotherby’s said earlier this year, and the auction house noted: “Although inclined to absolute privacy, he and his wife Wilhelmina belonged to an artistically inclined circle in the west end of the city... by the 1920s Middleton’s taste became more eclectic and adventurous and he began to buy paintings for himself by the European avant-garde.”

The Monet work, Etretat, L’Aigulle et La Porte d’Aval, is deemed to be worth £700,000 and was formerly in the collection of Valerie Middleton. The galleries (NGS) describe the rare pastel work as a “subtle and atmospheric work, a quiet masterpiece produced by the artist at a crucial transitional moment in his career”.

The AIL scheme enables taxpayers to transfer important works of art and other heritage objects into public ownership – it means that works of art that may be sold on the open market become part of the public domain.

Monet produced this work around 1885 at Etretat, famous for its rock formations such the Porte d’Aval and the Needle (Aiguille), featured in the National Gallery’s pastel.

He produced several versions in oil of the cliffs at Etretat and this period laid the ground for his “series” paintings of the 1890s, culminating in his more famous water lily paintings.

Monet frequently used chalk and pastel to develop ideas for his paintings or to produce independent works of art.

The NGS added in a statement: “Executed from a high vantage point, the pastel has an elegiac quality, expressed through the use of muted tones of blue, cream and brown, suggesting the approach of evening.”

The NGS has five works by Monet, all from earlier or later periods in his career.

Sir John Leighton, director general of the NGS, said: “This is the first work on paper by the outstanding French Impressionist Claude Monet (1840-1926) to enter the national collection.

“It provides a wonderful complement to the major paintings in oil by the artist already in Edinburgh and is an atmospheric composition of remarkable subtlety and interest.

“We are immensely grateful to everyone who has made possible its transference to public ownership through the AIL scheme.”