Juliet Nicolson was inspired to write The Perfect Summer while reading L P Hartley’s The Go-Between during the hot summer of 2003, which made her wonder whether it would be possible to convey ‘the vivid richness of how it smelt, looked, sounded, tasted and felt’ to be alive in such a summer. Edwardian England is often portrayed as one long summer’s afternoon, and this book is a biography of the summer of 1911, the hottest of them all. The London Season that year was more frenetic than ever. ‘It was such fun,’ gushed the socialite Mrs Hwfa Williams in her memoirs. But while the rich partied, the East End poor broiled in stinking slums and striking dockers brought the economy to a standstill. The sweltering summer was like an overripe fruit, a metaphor for the belle époque, the world that was about to end in the Armageddon of the First World War.