[Suzerain of Sheol]

Come to think of it, I don't think he's ever published any original works of his own. At least, if he has, I've never heard of them. He seems content to just re-use his father's work, though in his defense, he did have to do a lot of editing, since many of these stories were only in notes and fragments the Tolkien left behind.

I don't want to make it sound like he hasn't put a lot of work into the books that have gotten published, just that the core ideas aren't his. (We'll never know how much of the writing he did to fill in the gaps that J. R. R. left behind.)