Answer
Christopher Tolkien was an academic editor and philologist. He is best known for his work editing and publishing the posthumous writings of his father, J. R. R. Tolkien, including The Lord of the Rings, The Hobbit, and The Silmarillion. He also wrote his own works of fiction and non-fiction, including The History of Middle-earth, a twelve-volume series that chronicles the history of the world of Middle-earth.