The Legend of Sigurd and Gudrun

J.R.R Tolkien's 'The Legend of Sigurd and Gudrun' is a re-telling of this famous Norse tale which he wrote in the early 1930's (pre-'The Hobbit' and 'Lord of the Rings'), and was published for the first time in 2009. Christopher Tolkien has added many notes and a commentary alongside his father's work.

You can find an interview I gave about this book here