Well-known historian Lucy Worsley will give a talk on the opening night of a North Yorkshire festival later this year, organisers have announced.

She will speak about her biography of Agatha Christie at Richmond Walking and Book Festival in September, discussing why, despite all the evidence to the contrary, Christie presented herself as a retiring Edwardian lady of leisure.

Sharing her research based on the writer's personal letters and papers, Lucy will uncover the real Agatha Christie – the story of a person who, despite the obstacles of class and gender, became an astonishingly successful working woman.

Darlington and Stockton Times: The cover of Lucy Worsley's biography of Agatha Christie

Lucy is a household name, well known for her television and radio programmes on a wide range of subjects including lady killers, suffragettes, Sir Arthur Conan Doyle and Henry VIII's six wives. She is passionate about making history engaging to the widest possible audience, is co-chief curator at Historic Royal Palaces, and has an OBE for services to history. Her series, Suffragettes with Lucy Worsley, won a BAFTA.

Darlington and Stockton Times: Historian Lucy Worsley will speak at Richmond Walking and Books Festival on September 20 Picture: Paul Musso

Barbara Gravenor, chair of the Richmond Walking and Book Festival trustees, said: "We are delighted and very excited to welcome Lucy to the festival. It promises to be a memorable evening."

Her talk takes place on the evening of September 20 at Richmond School. Tickets cost £25 and will be available from May 13 for purchase by Friends of the Festival from booksandboots.org and on sale to the general public from May 20.

The festival, which was founded in 2005, will run this year from September 20 to 29 and is an annual celebration of books, walks and talks in the Yorkshire Dales.