https://www.theguardian.com/books/2020/jan/20/christopher-tolkien-obituary

Son of JRR Tolkien who edited much of his father’s posthumously published work including The Silmarillion

Christopher Tolkien, who has died aged 95, edited and published a huge body of writings left by his father, JRR Tolkien, extending the world of Middle-earth created in The Hobbit (1937) and The Lord of the Rings (1954-55), but also providing an unparallelled portrait of a creative life. Becoming literary executor upon his father’s death in 1973, Christopher took charge of 70 boxes of papers ranging from Oxford lectures to lexicons of invented Elvish.

A collection of the primary legends of Middle-earth, The Silmarillion, eagerly anticipated by legions of fans, had been worked and reworked since 1917, with constant evolutions in style, names and plot. Successive drafts, mostly unfinished, had been left in disorder. Christopher began a scholarly edition with variants and notes, but then recruited an assistant – Guy Gavriel Kay, a young Canadian family friend who is now a fantasy novelist. They decided to publish a single narrative without commentary, eliminating discrepancies including any with The Hobbit and The Lord of the Rings.