Keira Knightley is set to star in a new movie written by her playwright mother Sharman MaDdonald.

"The Best Time Of Our Lives" is based on a real-life incident in 1945 involving poet Dylan Thomas, his wife Caitlin, and couple Vera Phillips and her husband William Killick, when Killick was found with a machine gun and a grenade outside Thomas' home.

The Best Time Of Our Lives will be directed by John Maybury, who worked with The Pirates Of The Caribbean star in 2004's The Jacket, and Knightley will play the part of Vera, Thomas' childhood friend.

Excited about the film and the prospect of working with Maybury again, Knightley says, "I'm dying to do it."

MacDonald's script explains the complex background to the event, which left the famous poet and his wife shaken but unhurt.

Filming will begin next spring (2007), with the film expected to be released in 2008.