I was lying on the beach when I felt it fall into my lap. It was a breezy late-summer afternoon in northern Brittany and the tide was just starting to recede. Out of the corner of my eye, I could see empty oyster beds peeking from the waves and a few disconsolate gulls bobbing about on the swell. Somewhere, a little way off, my children were playing among the rockpools – fishing nets and buckets at the ready. And the stack of proofs I had left behind on my desk, waiting to be corrected, seemed a thousand lifetimes away.

It was one of those strange, languid moments that come upon you quite unexpectedly when you feel rather marooned. Time doesn’t stop exactly – nothing so clichéd – but ebbs and flows. As a boy, I’d spent more holidays than I care to remember sitting on a Welsh beach in trunks and a jumper, enjoying the wet sand oozing between my toes, without much thought for anything that came afterwards. And now, half a lifetime later, there I was, watching my own children and thinking about nothing but. What, I wondered, will they be like at my age? Will they remember that afternoon and think back to their laughter amid the rocks or will it just float away into forgetfulness, lost in the great ocean of childish memories? The thought vaguely troubled me.

I took out a book I’d been looking forward to reading for a while. I’d only recently managed to get hold of it. It was a copy of the Renaissance historian Francesco Guicciardini’s Storia d’Italia, written in 1537–40. This particular volume, published in Bari in 1929, was in magnificent