No. 1852, Confirmed by Breguet's Archive Records

A pendant watch of 26.7mm, small enough to sit in the hollow of a palm, and finished the way only a great Paris house finishes small things. The back is translucent royal-blue enamel over engine-turning, held inside a white enamel border, and at its centre sits a pinwheel rosette of rose-cut diamonds. The bezel repeats the blue and white around a gilt engine-turned dial with Breguet Arabic numerals and blued steel Breguet hands, the open-ring pattern the house itself invented. Everything about it was made to be worn against dark fabric on a long chain, and the chain is still here: the original sautoir of slender blue enamel batons spaced with seed pearls, closed by a diamond-set clasp. Chains of this kind are nearly always lost or separated over a century; a matching original changes what the piece is.

It is a Breguet of the Brown era, made in Paris and sold from the maison's salon at 2 rue Édouard VII in the spring of 1914. The house's registers record the sale, and the watch's return for service nine years later; the entry, confirmed in writing by Breguet, is set out in The Archive below. What the object adds to the paperwork is condition: the enamel still bright with only a few tiny chips, the rosette secure, the original crystal in place, the chain showing only light wear to a few links.

For all its jewellery, it is a proper watch. The keyless bar movement winds from the crown, sets by drawing it out, and runs correctly: a full lever-escapement mechanism folded into a case not much bigger than a coat button.

Pieces like this belong to a particular Paris, the last spring before the First World War, when a watch could be commissioned as a jewel and entered in a ledger by hand. This one has kept its enamel, its diamonds, its chain and its paper trail together for more than a century.

The marks, the movement and the condition are set out piece by piece in the drawers below; the register entry is set out in The Archive.