Part of a magnificent collection of jewellery that was believed to have been lost in the turmoil of the Russian revolution has been discovered in a dusty archive in the Swedish foreign ministry, where it had lain undisturbed for 91 years.

The jewellery belonged to Grand Duchess Maria Pavlovna, an aunt of the last tsar, who abandoned a sumptuous palace in St Petersburg and most of its treasures during the bloody chaos of civil war.

Only now has it emerged that she had secretly deposited part of her jewellery at the Swedish embassy for safe keeping before becoming the last of the Romanovs to flee Russia.

The treasure, which includes items crafted by Fabergé, is to be auctioned by Sotheby’s in London later this year. It was rediscovered during a renovation of the foreign ministry building.

The Swedes have returned the jewellery – including golden gem-encrusted cigarette cases and cufflinks – to descendants of the grand duchess, who are putting it up for sale in November. It is expected to raise about £1m.

“Unknown to generations until their recent rediscovery, the objects, some of which still contain evidence of use by the Romanovs, truly evoke the grandeur and sublime taste of their original owners,” a Sotheby’s spokesman said. “The allure of this intimate and precious group, with its links to historical events, will hold the highest appeal for discerning collectors.”

How the duchess managed to smuggle the rest of her jewellery out of Russia is the stuff of legend. According to William Clarke, author of Hidden Treasures of the Romanovs, the British aristocrat and diplomat Albert Henry Stopford, who was a close friend of Pavlovna, risked his life to break into her palace, locate the jewellery and carry it out under diplomatic immunity in his Gladstone bags.

The famous Vladimir tiara he saved from the Bolsheviks for the duchess is owned today by the Queen.

Pavlovna, who was born Duchess Marie of Mecklenburg-Schwerin, was renowned for her lavish receptions as St Petersburg’s most prominent hostess; even as her country disintegrated she refused to let standards drop. When an opportunity to escape via Constantinople presented itself, she declined to leave for fear of being subjected, like other refugees from her family, to the indignity of delousing.

She eventually boarded an Italian ship to Venice and from there travelled to France in 1920. She died the same year in her summer residence at the northeastern resort of Contrexéville.

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