An embroidered silk waistcoat celebrating a short-lived Anglo-French trade treaty acquired by the National Maritime Museum for €5000 (£3470) at Deburaux & Associés in Paris on February 11.

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The untailored waistcoat, presented in a rectangular glass case with giltwood frame, was woven in gros de Tours and embroidered in Lyon silk with a fanciful design featuring banners, ships, and alternating cockerels and leopards above the buttonholes.

Sale expert Aymeric de Villelume noted that the waistcoat commemorated a Traité de Commerce - the inscription appears on the banners near the bottom - but was unable to provide further details of the treaty in question, and dated the waistcoat to around 1780.

Pitt's deal

In fact, it must have been made a few years later: the treaty in question was the Eden Treaty of 1786, concluded between French Foreign Minister the Comte de Vergennes (1719-87), a disciple of the Philosophes, and Prime Minister William Pitt the Younger, who was influenced by Adam Smith's economic liberalism and who feared a decline in trade with the newly independent America.

The bottom of the waistcoat is embroidered with ships, bales of cotton and barrels of Vin de Bordeaux - a reference to the terms of the Treaty, which slashed duty on British textiles and pottery on the one hand; and on French wine, brandy, oil and vinegar on the other, to put an end to a century of Anglo-French commercial rivalry.

The Treaty was widely perceived as being to England's advantage (French silks, for instance, did not benefit from the new low tariffs) and was never popular in France. It was one of the grievances listed by the States General in 1789, and later blamed by Napoleon for bankrupting France and helping cause the Revolution. Some historians dispute that assessment, but the entente's cordiality soon dissolved. When war broke out between France and England in 1793, all British goods in France were seized, and anyone found storing them was clapped in irons.

Villelume believes that several similar waistcoats were made, doubtless as souvenirs for those involved in drafting the Treaty.

This one had been in the same French family since 1810, and was in fine condition, though the colours weren't perfect. "Nothing a good clean shouldn't sort out," said Villelume.

The waistcoat aroused scant private interest but was targeted by several other museums - a representative of a German museum was bidding in the room; the Paris Museum of Fashion & Textiles stayed in the hunt to €4000; while the Legion of Honor museum in San Francisco contacted Villelume just after the sale in the mistaken belief it could still acquire the piece.

California's loss is London's gain. The National Maritime Museum are delighted with this latest contribution to cross-Channel trade. A museum spokesperson said the waistcoat would be going into conservation, then storage, prior to appearing as a key exhibit in a forthcoming new gallery.

Simon Hewitt