Unfinished Tales, by J.R.R. Tolkien (1998 edition), paperback fantasy anthology
“Further tales that expand The Silmarillion and The Lord of the Rings
This collection ranges from the time of The Silmarillion to the end of the War of the Ring in The Lord of the Rings. Its many treasures include Gandalf’s lively account of how he came to send the Dwarves to the celebrated party at Bag-End, the emergence of the sea-god Ulmo before Tuor, the only story of Numenor before its fall, and all that is known of the Five Wizards.
The collection has been edited by Christopher Tolkien, who provides a commentary placing each of the Tales in the context of his father’s work.”