Dame Kristin Scott Thomas has been left drop-jawed after learning her humble grandfather was a Second World War hero who saved thousands of soldiers from the beaches of Dunkirk.
Captain William Scott Thomas would always flatly refuse to discuss his wartime experiences with his granddaughter, stonewalling the topic as 'off limits'.
But more than 30 years after his death, the Bafta-winning actress has unearthed the truth about her grandfather's staggering accomplishments during the bloody conflict.
Dame Kristin Scott Thomas has been left drop-jawed after learning her humble grandfather was a Second World War hero who saved thousands of soldiers from the beaches of Dunkirk
Captain William Scott Thomas (pictured with her aunt) would always flatly refuse to discuss his wartime experiences with his granddaughter, stonewalling the topic as 'off limits'
Actress Kristin Scott Thomas's grandfather William and grandmother Mary on their wedding day in 1931
In a Channel 4 documentary called My Grandparents War, Dame Kristin was overwhelmed with emotion to be told that her grandfather captained the HMS Impulsive into the treacherous waters off Dunkirk as part of the daring Operation Dynamo in May 1940.
The naval ship successfully evacuated over 2,900 stranded troops after dodging bombs which were being dropped from the sky by the German Luftwaffe.
'He was a very different person from the person we understand this man to have been.'
Dame Kristin meets World War Two veteran David Caink, who served on board the same ship HMS Verulam as her grandfather
The Four Weddings And A Funeral star said she was shocked to learn the truth of her grandfather's war heroism when casting her mind back to their conversations in Flintshire, Wales, to how he used to ban talking about it.
Dame Kristin leaned heavily on her grandfather following the death of her father, a Royal Navy pilot who died on a training exercise in 1966.
The future actress' mother Deborah married another pilot, who in a horrible twist of fate also lost his life in an airborne accident.
In the third episode of the TV documentary series, historian Nick Hewitt revealed the truth about Captain Scott Thomas's war effort, for which he was awarded the service cross.