The first in a series of three programmes asking what we get from reading, and writing, diaries.

Writing a diary can be dangerous. As can reading one. Richard E Grant, a diarist since childhood, uncovers the power of the diary. He considers the diaries of Joe Orton, Kenneth Williams, Erwin James, John Diamond and Rosemary Ackland and asks whether a diary should, or could, ever be totally honest, wholly accurate and absolutely true.

Richard talks with Joe Orton’s sister, Leonie, about her long-held belief that Orton’s confessional diary was actually responsible for him losing his life. Richard also meets prison diarist Erwin James to understand the power of writing for a serving offender. Joss Ackland tells Richard about editing his wife’s 50-plus years of diary writing. And Richard meets with Sheila Hancock to talk about Kenneth Williams’ diary, in which she appeared many times. Williams had a charming public face. But in the diaries he could be savage. He even wrote that he’d never again speak to Sheila Hancock.

Click here to watch some scenes from the show.