I have just spent a most pleasant evening with my children learning all about the beautiful and tragic Tennyson poem The Lady of Shalott. First I read the poem out loud to them. Then we listened to the Loreena McKennitt song while we followed along in the book. Then we googled for images and found many, including the one above by Yang Zhang which is very similar to the one by Waterhouse but much cleaner and with a lovelier Lady.
The Lady of Shalott knows that there is a curse on her if she looks out the window down into Camelot so she sits at her loom weaving a magic tapestry looking at the images she sees in her magic mirror of the people that travel in and out of Camelot. She is content for a while but soon becomes weary of looking at the lives of others. One day she sees Sir Lancelot reflected within the mirror's frame. As she looks out the window at the real Knight her mirror cracks and the curse is in effect. So she writes her name on the side of a boat and floats down to Camelot, singing a song with her final breath. When Sir Lancelot sees her dead in her boat he says a blessing to her.
To see some of the rich artwork inspired by the poem and to read it for yourself check out this site. I encourage you to read the commentary as well. It is very interesting stuff.
This is just one of a series of Tennyson poems in connection with legendary King Arthur that I am reading for the Arthurian Challenge.