I arrive at Villa le Corti at 9 a.m. Clotilde orders coffee and I am soon settled down in a tepidly heated room and introduced to the archivist, Nada Bacic, originally from Croatia. As she pours espresso from a silver pot, we speak Italian, each with our foreign accents, and then set off into the past. The archive is spread through a half-dozen rooms, some little more than cubbies, others as grand as they are cold, one with a taxidermied eagle hanging from the ceiling. Stone stairs and oaken doors abound.

In the bottom left corner of the smallest room are Matteo Corsini’s “Recollections” but this is a copy, made in 1475. The difference between a merchant’s handwriting and a scrivener’s is clear enough, the one scrawled and bold, the other neat and careful. In any event, Italian calligraphy has changed so much since then that both are largely illegible to anyone who isn’t an expert. To digitize here would cost a fortune and take an age.

Opening an early tome, I stumble on the last will and testament of Cardinal Pietro Corsini who died in 1403. Written in both Latin and Italian, it fills a thick book 18 inches tall. The fine clothes he is dressed in for burial, the cardinal warns, must not be removed from his body. Two hundred gold florins are left to a monastery, on condition that the monks recognize a “solemn obligation” to say prayers for the cardinal’s soul “in perpetuity.”

After various commercial ups and downs the Corsinis consolidated their fortune in the 16th century when three brothers, Filippo, Bartolomeo and Lorenzo, simultaneously ran three merchant banks in London, Lyons and Florence. Bacic asks my help to shift a 15-foot-long bench, behind which the brothers’ correspondence is stacked in a dozen mammoth white-and-gold folders. Some of the messages are coded, substituting numbers for letters, to protect business secrets. In 1579, I read, a consignment of wool has disappeared from a ship in Lisbon. In 1583 Bartolomeo in Lyons reports being feverish and sweating through three shirts every night. “But our business in Naples is going well,” he assures Filippo in London.

Along with the letters is a slim account book listing Bartolomeo’s donations to religious institutions on an almost daily basis. At the end of each page, the entries are added up and carried over. In the months before his death, the sums are notably larger.