Morning children. Are you sitting comfortably? Then I'll begin.

The story of the von Trapps' escape from the Nazis is well known, thanks to "The Sound of Music", but not everyone realises that it's based on a true story. Maria Kutschera, a novice in an Austrian convent, was asked to teach the seven children of the widowed naval commander Georg von Trapp. They were married in 1927 - when he was 47 and she 22 - and had three children together.

The family lost most of its wealth in the 1932 crash and began singing to raise money. Their fame brought invitations to sing all over Europe, including a request for them to perform at Hitler's birthday party, which was declined.

Horrified by the 1938 annexation of Austria, the family fled by train to Italy and from there to the United States, where they set up home. Georg died of lung cancer in 1947.

Maria's memoir, "The Story of the Trapp Family Singers", was published in 1949. It inspired two films in Germany - "Die Trapp-Familie" (1956) and "Die Trapp-Familie in Amerika" (1958) - as well as Rodgers and Hammerstein's 1959 Broadway musical "The Sound of Music" and Robert Wise's 1965 film version.

Maria and her children and step-children continued to run the Trapp Family Lodge in Stowe, Vermont (which now hosts the annual Vermont Mozart Festival). She died twenty years ago today.