In J. R. R. Tolkien's legendarium, the Elves or Quendi are a sundered (divided) people. They awoke at Cuiviénen on the continent of Middle-earth, where they were divided into three tribes: Minyar (the Firsts), Tatyar (the Seconds) and Nelyar (the Thirds). After some time, they were summoned by Oromë to live with the Valar in Valinor, on Aman. That summoning and the Great Journey that followed split the Elves into two main groups (and many minor ones), which were never fully reunited.

Tolkien stated that the stories were made to create a world for his elvish languages, not the reverse. The Tolkien scholar Tom Shippey writes that The Silmarillion derived from the linguistic relationship between the two languages, Quenya and Sindarin, of the divided Elves. The Tolkien scholar Verlyn Flieger states that Tolkien used the Indo-European type of proto-language as his model. In her view, the sundering of the Elves reflects the progressive decline and fall in Middle-earth from its initial perfection; the highest Elves are those who deviated least from that state, meaning that in Tolkien's scheme, ancestry is a guide to character.

J. R. R. Tolkien (1892–1973) is best known as the author of the high fantasy works The Hobbit and The Lord of the Rings. He was a professional philologist, an expert in the changes in words between languages. He created a family of invented languages for Elves, carefully designing the differences between them to reflect their distance from their imaginary common origin. He stated that his languages led him to create the invented mythology of The Silmarillion, to provide a world in which his languages could have existed. In that world, the splintering of the Elvish peoples mirrored the fragmentation of their languages.

In Tolkien's legendarium, the Elves awoke at Cuiviénen, a bay on the eastern side of the Sea of Helcar, on the continent of Middle-earth, where they were divided into three tribes: Minyar (the Firsts), Tatyar (the Seconds) and Nelyar (the Thirds). After some time, they were summoned by the Vala Oromë, the huntsman, to live with him and the other Valar in Valinor, on Aman. The Eldar are those who accepted the summons. Their name, literally Star People, was given to them by Oromë, in their own language, Primitive Quendian. The Avari are those who refused the summons. Half of the Avari (the "refusers") came from the largest tribe, the Nelyar, but most of the Nelyar went on the journey.

The Eldar migrated westwards across the north of Middle-earth in their three groups. The Minyar became known as the Vanyar, meaning the Fair Elves, with golden-blond hair. The Tatyar who migrated west became known as the Noldor or Deep Elves, with deep knowledge of crafts and skills. The Nelyar who went west were known as the Teleri (Those who come last) or, as they called themselves, the Lindar or Singers. They stayed on the east of Aman, in Tol Eressëa.

Those of the Teleri who reached Beleriand by the Great Sea but chose not to cross to Valinor were later called the Sindar (Grey Elves); their language was Sindarin. They stayed in the west of Middle-earth and were ruled by Thingol (Elwë). Many of the Sindar chose to remain behind to look for their lord Thingol, who disappeared near the end of the journey. These later inhabited Doriath, and were named the Iathrim or People of the Girdle, for the magical 'Girdle of Melian' that surrounded and protected the kingdom.

Those who came to the shores of the Great Sea of Belegaer but decided to stay there, or who arrived too late to be ferried, were called the Falathrim (People of the Shore). They were ruled by Círdan the Shipwright.

Those who chose to remain behind and populated the lands to the north-west of Beleriand were called the Mithrim or Grey People, giving their name to the region and the great lake there. Most of them later merged with the Noldor who returned to Middle-earth, especially those of Gondolin. Those who reached Aman were called Amanyar Teleri; they were also called the Falmari, the People of the Waves, expert with ships and the sea.