Walking into Cartier’s elegant London headquarters on New Bond Street feels like stepping into the pages of history. This five-storey Victorian building, all wood panelling and ornate cornicing, has been home to Cartier for more than 100 years, and its past is deeply bound up with the history of the company. Jacques Cartier, grandson of the founder, Louis-François, had selected the address to become one of Cartier’s ‘temples’ of luxury, alongside the headquarters in Paris and New York run by his brothers Louis and Pierre respectively.

This, though, is not just a place synonymous with a bygone era of gem-encrusted tiaras and elegant pocket watches: global history on occasion stepped right through the doors of 175-177 New Bond Street. No company was unchanged by the great cataclysm of the Second World War, but there can be few luxury marques whose wartime experience was so extraordinary, and which left such a mark on the identity of the company in the years that followed.

My guide through Cartier’s war is Jenny Rourke, the company’s London archivist, who leads me up the magnificent mahogany staircase to the fourth floor, where, in the eaves under a mansard roof, live Cartier’s archives. The room is bright and airy, its shelves packed with green ledgers in which every item of jewellery made by the firm’s London operations is recorded, from the gifts bought by Edward VIII for Wallis Simpson – the gem-set cross bracelet Simpson wore on their wedding day, each charm inscribed with a note such as ‘God save the King for Wallis’ – to the fabled Patiala necklace, made for the Maharaja of Patiala and containing the world’s seventh-largest diamond (along with nearly 3,000 others), which was lost in the years following the Second World War.