Colin Gleadell pays attention to the much overlooked 19th Century sales in London, especially this tale of a Peder Severin Kroyer work that bubbled up through the dealer community:

One of his masterpieces, Summer Evening at the South Beach, Skagen, dated 1893 and in the Skagens Museum, is of his wife, Marie, and Anna Ancher, the wife of fellow painter Michael Ancher, walking arm in arm along the beach at Skagen after a dinner, elegant white figures in a misty haze of blue. For this, we now know, he painted four studies, three of which were previously known from photographs. The newly discovered fourth, unsigned, very grubby, and hanging loosely from its stretcher, was overlooked by Christie’s when it was offered as part of the collection of Princess Maria Beatrice of Savoy, the youngest daughter of Umberto the Second, the last king of Italy, at its South Kensington branch on April Fool’s day. Here it was catalogued as “after Kroyer” (ie a copy) with an estimate of £2,000 to £3,000.

However, more than one pair of eagle eyes had spotted its potential, and it was bought by a UK dealer for £75,000. Seven months later, after some restoration and research which identified the painting as a genuine study for his masterpiece, Sotheby’s offered it with a £150,000 to £250,000 estimate before selling it for £493,250 – the second-highest auction price for a work by Kroyer.