Sometimes, a chance encounter in the bookshelves - typically, coming across a forgotten volume while searching for something else altogether - triggers a serpentine, serendipitous train of thought which ends up connecting unexpected destinations, like the Underground map. This is one of those journeys.

It begins not with a book but with a pamphlet, privately published and finely printed by Vivian Ridler, called Hong Kong Portraits by C.J. Driver. When this appeared, in 1986, I was invited to review it for the journal of the Headmasters' Conference, an improbable but in fact perfectly logical assignment: at the time, Jonty Driver was Headmaster of Berkhamstead School (he subsequently became Master of Wellington); over twenty years earlier, I had been one of his first sixth-form students at Sevenoaks. There was a nice symmetry in a poet who had been a teacher reviewing a poet, now a headmaster, who had once taught him. I hadn't much space, but clearly I ought to combine something about the poems with a touch of reminiscence - that was then, this is now - which would show how a young firebrand had been transformed (as is often the way with firebrands) into a notably successful pillar of the public school establishment.

Jonty Driver arrived in Kent in September 1964, immediately following his release from ninety days' solitary confinement in Cape Town, where he had been President of the National Union of South African Students: these were uncommon CV entries, even by the ...