November 29, 1971...
was a sad day in the life of the Professor....

I am grieved to tell you that my wife died this morning. Her courage and determination (of which you speak truly) carried her through to what seemed the brink of recovery, but a sudden relapse occurred which she fought for nearly three days in vain. She died at last in peace.
I am utterly bereaved, and cannot yet lift up heart, but my family is gathering round me and many friends.

J.R.R. Tolkien to William Cater

She was (and knew she was) my Lúthien.

J.R.R. Tolkien to Christopher Tolkien, July 11, 1972