In the fall of 1988, I found myself in Calcutta for a few days. Put that way, it sounds as if I just wandered there, but in fact I was meeting a group that was going trekking in Bhutan and our flight left from Calcutta. I took advantage of the stopover to visit various monuments to the British Raj of which Calcutta had been the capital. One of the places I especially wanted to visit was the South Park Street Cemetery, whose memorial tombs are practically an encapsulated history of the Raj, although it is somewhat off the usual tourist route. It was opened in 1767. People like Charles Dickens’s second son, Walter Landor Dickens and William Thackeray’s father, Richmond, are buried there. Most of the people who are buried there died young, and if I had to list the cause of death I would write “India”—India was too much for many of them.

My immediate problem was how to find ...