For 60 years Mr George Leo John Lucas led a double life. By day, he was a civil servant at the Board of Trade, but by night – unable to live openly as a gay man before the Sexual Offences Act of 1967 – he was a fixture of London’s colourful underground gay scene, a twilight world of petty crime, louche pubs and public lavatories. He was also an obsessive diary writer.

When Mr Lucas died in 2014 he left his diaries to the journalist Hugo Greenhalgh. This book combines Mr Lucas’s deliciously indiscreet entries over the course of the 1960s with Greenhalgh’s razor-sharp historical insights. Together they give a vivid, one-of-a-kind account of gay life that has been overlooked.