ITV is to celebrate Princess Anne's 70th birthday next month with a one-off documentary.

The 90-minute Princess Royal: Anne at 70 has been filmed over the last year and will feature previously-unseen footage as well as interviews with Anne, her children Peter Phillips and Zara Tindall, and close friends.

The documentary will recount the major events in the life of The Queen's eldest daughter, including her role in Team GB's Olympics equestrian team, her charity endeavours and the infamous failed kidnap attempt of 1974.

Jo Clinton-Davis, ITV's controller of factual, said: "With exclusive, up close and extensive access to Princess Anne, her family and those closest to her, this fascinating film is a landmark event on a landmark birthday."

The programme is expected to air on or near to Anne's birthday on Saturday, August 15.