Timeline

The play, The Mousetrap entered the record books over 50 years ago in 1958 when it became the longest-running show in the history of British theatre.

It is still running and is the longest-running show of all time. It ranks with Buckingham Palace, The Tower of London, St Paul’s and others as a “must see” for tourists visiting London. When it started, Churchill was British prime minister; Stalin ruled Russia and Truman was still president of the United States.
Apart from it being a “victim of its own success”, it is difficult to explain its longevity. It is not a great play but it has been seen by over 10 million people and has never once missed a performance.
It has all the twists and turns you would expect from its author, Agatha Christie, and her fame has played a part in its success.
It was originally written as a radio drama. Queen Mary was asked by the BBC what she would like for her 80th birthday and she asked for an Agatha Christie play. Christie wrote a 30-minute radio play called Three Blind Mice, which she later rewrote for stage as The Mousetrap.
Years later, the play was again a present when Christie brought her nephew to lunch and handed him a parcel saying, “This is a little present for you,” – the script of The Mousetrap. Two men who were not so lucky bought the film rights of the play in 1956. There was a condition in the contract that the film could not be made until the play ended its run.
The original cast included Sir Richard Attenborough as Detective Sergeant Trotter and David Raven as Major Metcalf. Raven entered the record books by playing the part for 4,575 performances. Likewise, actress Nancy Seabrooke, while never actually in the cast was understudy for the part of Mrs Boyle for 15 years, or 6,240 performances.
Since Raven retired, the cast is changed each year. There are no star actors and almost 400 actors and actresses have appeared in the play. For the cast it is steady work and a chance to be part of theatrical history.
The Mousetrap is set in a newly opened guesthouse. The owners are inexperienced and are nervously awaiting the arrival of their first guests.
A radio newscast reports the murder of a woman in London and give a description of a man the police wish to interview.
As the report is played, the audience see the first guest arriving and he exactly fits the description on the radio. In fact, the radio announcement is still the same one used on the first night. 
The detective arrives and in true Christie fashion, assembles the guests and solves the murder.
At the end of each production the cast take a curtain call and the murderer addresses the audience. He tells them that they are part of the conspiracy and that they must never reveal “whodunit”. I saw the play about 20 years ago and I cannot tell you the guilty one. To be honest, I forget.
The Mousetrap, a must-see for visitors to London and a piece of theatrical history, opened its record-breaking run in The Ambassador Theatre on November 25, 1952 – 57 years ago this week.