The Silmarillion in the context of "Frodo Baggins"

Sauron (/ˈsaʊərɒn/) is the title character and the main antagonist in J. R. R. Tolkien's The Lord of the Rings, where he rules the land of Mordor. He has the ambition of ruling the whole of Middle-earth using the power of the One Ring, which he has lost and seeks to recapture. In the same work, he is identified as the "Necromancer" of Tolkien's earlier novel The Hobbit. The Silmarillion describes him as the chief lieutenant of the first Dark Lord, Morgoth. Tolkien noted that the Ainur, the "angelic" powers of his constructed myth, "were capable of many degrees of error and failing", but by far the worst was "the absolute Satanic rebellion and evil of Morgoth and his satellite Sauron". Sauron appears most often as "the Eye", as if disembodied.

Tolkien, while denying that absolute evil could exist, stated that Sauron came as near to a wholly evil will as was possible. Commentators have compared Sauron to the title character of Bram Stoker's 1897 novel Dracula, and to Balor of the Evil Eye in Irish mythology. Sauron is briefly seen in a humanoid form in Peter Jackson's film trilogy, which otherwise shows him as a disembodied, flaming Eye.

In the fantasy of J. R. R. Tolkien, the Dwarves are a race inhabiting Middle-earth, the central continent of Arda in an imagined mythological past. They are based on the dwarfs of Germanic myths who were small humanoids that lived in mountains, practising mining, metallurgy, blacksmithing and jewellery. Tolkien described them as tough, warlike, and lovers of stone and craftsmanship.

The origins of Tolkien's Dwarves can be traced to Norse mythology; Tolkien also mentioned a connection with Jewish history and language.Dwarves appear in his books The Hobbit (1937), The Lord of the Rings (1954–55), and the posthumously published The Silmarillion (1977), Unfinished Tales (1980), and The History of Middle-earth series (1983–96), the last three edited by his son Christopher Tolkien.

In J. R. R. Tolkien's writings, Elves are the first fictional race to appear in Middle-earth. Unlike Men and Dwarves, Elves do not die of disease or old age. Should they die in battle or of grief, their souls go to the Halls of Mandos in Aman. After a long life in Middle-earth, Elves yearn for the Earthly Paradise of Valinor, and can sail there from the Grey Havens. They are prominent in The Hobbit and The Lord of the Rings, and their history is described in detail in The Silmarillion.

Tolkien derived Elves from mentions in the ancient poetry and languages of Northern Europe, especially Old English. These suggested to him that Elves were large, dangerous, beautiful, lived in wild natural places, and practised archery. He invented languages for the Elves, including Sindarin and Quenya.

J. R. R. Tolkien's fantasy books on Middle-earth, especially The Lord of the Rings and The Silmarillion, drew on a wide array of influences including language, Christianity, mythology, archaeology, ancient and modern literature, and personal experience. He was inspired primarily by his profession, philology; his work centred on the study of Old English literature, especially Beowulf, and he acknowledged its importance to his writings.

He was a gifted linguist, influenced by Germanic, Celtic, Finnish, Slavic, and Greek language and mythology. His fiction reflected his Christian beliefs and his early reading of adventure stories and fantasy books. Commentators have attempted to identify many literary and topological antecedents for characters, places and events in Tolkien's writings. Some writers were certainly important to him, including the Arts and Crafts polymath William Morris, and he undoubtedly made use of some real place-names, such as Bag End, the name of his aunt's home.

J. R. R. Tolkien built a process of decline and fall in Middle-earth into both The Silmarillion and The Lord of the Rings.

The pattern is expressed in several ways, including the splintering of the light provided by the Creator, Eru Iluvatar, into progressively smaller parts; the fragmentation of languages and peoples, especially the Elves, who are split into many groups; the successive falls, starting with that of the angelic spirit Melkor, and followed by the destruction of the two Lamps of Middle-earth and then of the Two Trees of Valinor, the destruction of Gondolin, and the cataclysmic fall of Númenor.

The Old Straight Road, the Straight Road, the Lost Road, or the Lost Straight Road, is J. R. R. Tolkien's conception, in his fantasy world of Arda, that his Elves are able to sail to the earthly paradise of Valinor, realm of the godlike Valar. The tale is mentioned in The Silmarillion and in The Lord of the Rings, and documented in The Lost Road and Other Writings. The Elves are immortal, but may grow weary of the world, and then sail across the Great Sea to reach Valinor. The men of Númenor are persuaded by Sauron, servant of the first Dark Lord Melkor, to attack Valinor to get the immortality they feel should be theirs. The Valar ask for help from the creator, Eru Ilúvatar. He destroys Númenor and its army, in the process reshaping Arda into a sphere, and separating it and its continent of Middle-earth from Valinor so that men can no longer reach it. Elves can still set sail from the shores of Middle-earth in ships, bound for Valinor: they sail into the Uttermost West, following the Old Straight Road.

Scholars have noted the importance of the theme to Tolkien, as he revisited it repeatedly. His early mention of the Straight Road as being a level bridge recalls Bifröst, the bridge between the earthly Midgard and the gods' home of Asgard in Norse mythology. Other possible inspirations for the theme include a literary crux in Beowulf in the shape of the character Scyld Scefing. He arrives in the world as a baby in a boat filled with gifts, and he departs from it in a ship-burial, with the odd feature that the ship is not set on fire, as in the typical Viking ritual. The scholar Tom Shippey suggests that Tolkien may have felt that Scyld is being sent back to the gods across the Western sea via a kind of Straight Road, and that Tolkien perhaps created his Valar and their home Valinor to explain that gap in Beowulf. His poem "A Walking Song", which occurs in different versions at the start and end of The Lord of the Rings, also alludes to the theme.