Fiction by Anita Shreve.
This story begins with a woman in France during the first world war. She is wounded and has lost her memory, but she says her name is Stella Bain. It turns out it isn't.
This was a good book, but not as good as others I've read by this author. Check out The Pilot's Wife or The Last Time They Met instead.
I also read recently by this author: A Change in Altitude