"Based on the appendices of The Lord of the Rings books, The Rings of Power explores stories like the forging of the great rings, Sauron's emergence of Middle Earth and the fall of Númenor. Season two of the series is expected to be released in 2024.

Amazon holds the rights to adapt the Second Age of Middle Earth, hence its focus on the events set out in the appendices of the Lord of the Rings. Here's where it gets tricky, though. Amazon does not hold the rights to The Silmarillion.."

Before the first season was released, showrunners Patrick McKay and J.D. Payne explained this to Vanity Fair by saying: "We do not have the rights to The Silmarillion, Unfinished Tales, The History of Middle-Earth, or any of those other books… We worked in conjunction with world-renowned Tolkien scholars and the Tolkien estate to make sure that the ways we connected the dots were Tolkien-ian and gelled with the experts’ and the estate’s understanding of the material."

Now, some of the events in The Silmarillion are included in the appendices, such as the fall of Númenor, so these events can be adapted by Amazon — but anything else is off limits. Jackson faced a similar issue with his films, hence why when Radagast the Brown was introduced in The Hobbit there were careful steps made to ensure that other wizards, who appear in The Silmarillion, were not mentioned.

It all seems very complicated, but the basic gist of it is this: Warner Bros. has the right to make films based on The Lord of the Rings, The Hobbit and the events in Third Age of Middle Earth, while Amazon has the TV rights to the Second Age of Middle Earth as set out in those books.

No one has the film or TV adaptation rights for The Silmarillion, or other books by Tolkien, as the Tolkien estate has chosen not to sell these."