Oh yes it is

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Ahem, it's not too long but it does go into a bit of detail. I enjoyed it though, I like reading background stories and so-on.
It starts off with the creation story and tells us about the creator etc.
Basically it's the history of the first few ages, before we pick up the story of LOTR.
It tells of the first Dark Lord, of whom Sauron was only a servant, and his epic battle with the elves of Middle Earth.
It also focuses on where the elves come from, and gives a little background on Elrond's father etc.
Also follows the exile of men.