I get writers to sign their books,” says Louis Auchincloss, reaching up to a shelf of immaculate first editions. Just shy of his 90th birthday, he is now the “grand old man” of American letters – older than Norman Mailer (84), Gore Vidal (82), Tom Wolfe (77), John Updike (75) and Philip Roth (74) – and in rude health, apart from his hips, the only act of betrayal wrought by age. He is alone – his wife Adele, an artist and a commissioner of New York’s public parks, died in 1991. Their three sons are grown up, and he has a granddaughter just starting at Yale.

He is confined to his apartment atop a solid 14-storey building on 90th and Park Avenue, one of the red-brick repository boxes of old money and old New York. The Upper East Side, the golden mile of American power and privilege, is to his south and west. It is this world, the locus of power and privilege for much of America’s history, that he has chronicled and dissected for 60 years, and now he is shut off from it until after his surgery. Bored, and decidedly irritated by his confinement, he turns energetically to the past.