, with the Australian actress .
In 2015, he starred in a mini-series on Gallipoli as Henry Nevinson.
Nicholas has remained close to all his The Sound of Music co-stars and was very fond of Charmian Carr.
Nicholas Hammond is still acting today Credit: Getty Heather Menzies: Louisa von Trapp Heather was born in Toronto and made her film debut, at 13, as Louisa von Trapp.
She went on to star in various TV shows, including classic sci-fi series Logan’s run, in which she played Jessica.
Heather also modelled for Playboy.
After a failed marriage to John Cluett she met her second husband, actor Robert Urich, while making a corned beef commercial - they married in 1975.
Heather later stepped away from the limelight to raise her three kids.
The mother and grandmother died at the age of 68 on Christmas Eve, 2017 after she was diagnosed with brain cancer.
Heather Menzies was Louisa the wilful third child Duane Chase: Kurt von Trapp Duane was born in Los Angeles and started acting at the age of 11 but, after starring in The Sound Of Music, the young child returned to school.
After High School Duane joined the United States Forest Service, where he fought forest fires, before going back to University to gain a Master's degree in geology.
Now 71, Duane lives in Washington with his wife Petra Maria and is returning to wildlife and forestry work after time spent designing computer software for oil and mining companies.
Duane quite acting to become a computer whizz Credit: Splash Angela Cartwright: Brigitta Von Trapp The only British von Trapp, Angela, 69, was born in Cheshire in 1952 but moved to the US at a young age to appear in TV series Make Room For Daddy.
After landing the role of Brigitta in the movie, at the age of 12, she went on to star in hit TV series Lost in Space from 1965–1968 and was cast in the television movies Scout's Honor in 1980.
She has been married to actor and producer Steve Gullion for 44 years and they have two children.
Angela’s acting career tailed off in the 1980s and she is now an artist, displaying her work at Studio City, Los Angeles.
Brigitta was played by Angela Cartwright Credit: Getty Debbie Turner: Marta von Trapp Debbie Turner, now 65, played six-year-old Marta von Trapp in the movie, the first child to take to Maria.
Although she had been acting in commercials from the age of six months, she gave up showbiz straight after The Sound of Music to concentrate on studying.
After graduating from college in California she worked in a ski resort where she met her husband Rick Larson. They married in 1980.
The couple have four daughters and live in Minnesota where Debbie runs her own event design company now known as Debbie Turner Originals.
Debbie Turner was sixth child Marta Credit: Getty Kym Karath: Gretl Von Trapp The cutest little von Trapp of the lot. Kym was six when she landed the role of Gretl but she was already an established actor, having starred in Spencer's Mountain with Henry Fonda at the age of three.
Karath has said she still is not fond of water after nearly drowning in the boat scene in The Sound of Music, as she could not swim.
Karath graduated from the University of Southern California with a degree in humanities, and shortly after that she moved to Paris, France, where she studied art history and modeled.
At the age of 26, she married Philippe L'Equilbec; their son was born in 1991.
Karen, now 63, left acting for a while and lived in Greenwich, Connecticut, before returning to the screen in 2005.
Little Gretl was the youngest of the singing clan, played by Kym Karath Credit: Getty