There’s one other trace of her, and quite a significant one at that: her savings book. It was among the family documents piled up in my father’s cellar. From it, I learn that she was both wealthy and frugal. That she deposited 3850 francs on 14 March 1871 at the Paris-Montparnasse branch, and another 6000 francs on 26 March, namely a week before my grandfather’s birth; that’s what made me think that brother-in-law Jules, who had been appointed to buy Botquelen, must have filched some of the money from the de Rignys, seeing as the amount of those two deposits was considerably greater than the 8000-franc price that appeared on the deed of sale.

Five days after the publication of my father’s death notice, while I was busy packing up boxes and fighting a furious wish to burn it all, I got a call from my girlfriend Tiphaine, who works at the town hall. Some smooth type in a suit and tie was looking up my family records in the island’s births, deaths and marriages register at that very moment.

The death notice I’d posted in Ouest-France must have alerted somebody, I said to myself. For somebody to have come all the way to the arsehole of the Iroise, looking for us, the down-and-outters of Brittany, some testamentary panic must have been set off among the authorised representatives of the de Rigny family.

Using the same methodology as you do with families, it’s possible to trace a company’s genealogy on the internet through the archives of the Trade and Companies Register.

The business known as the Établissements de Rigny at the time my forebear was acquired became De Rigny Construction in 1890 following two capital increases, one of which took place right in the middle of the Prussian occupation. Then it became RGL Construction in 1908, when Ferdinand de Rigny merged with Gireur and Legros from the École Polytechnique, one of whom would go on to marry his daughter.

In the first half of the twentieth century, the company which was now known only as RGL expanded its corporate purpose: in addition to public works, it developed a taste for mining concessions and energy supply. I learnt from another source – the archives of the Purge Commission – that the company, or rather, its manager, Guillaume de Rigny, Ferdinand’s youngest son and father of the late Philippe, had various legal issues after the war, struggling to explain how he had managed to effect four capital increases between 1940 and 1944, but it can’t have been too serious, as the prosecutor responsible for the file was removed before the matter went anywhere.