Baroness Maria Augusta von Trapp was the stepmother and matriarch of the Trapp Family Singers. Her story served as the inspiration for a 1956 German film that in turn inspired the Broadway musical The Sound of Music.—Source
Honestly, I can't rate this one. I bought it years ago and never used it for anything at all. It has been on my bookshelf until this morning, when I'm pulling it to take to donate.