The third clan was the largest of the three houses of the Elves, and most of the Avari originally belonged to this clan.
In ancient times they named themselves Lindar, or "Singers", because they were known for their fair voices.
The Sindar of Beleriand called themselves simply Edhel, which means Elf, and is related to the Quenya word Elda of the same meaning.
The Teleri were sundered from the first two clans, the Vanyar and the Noldor, because they tarried behind searching for their lost king Elwë (later known as Thingol), and the first two clans were ferried across to Valinor on a huge island before the Teleri arrived in Beleriand. The Maia Ossë kept them company while they waited, and became their friend. Later when Ulmo returned with the island ferry, the Teleri had grown to love the sea, and Ossë convinced Ulmo to anchor the island in the bay of Eldamar, off the shores of Aman. The Teleri long remained on this Lonely Isle, and their language changed in different ways from that of the Vanyar and Noldor. Much later the Teleri learned to build ships, and finally made it to Aman, but their language remained different from Quenya.
The Teleri refused to join the Noldor in leaving Valinor, and many of them were cruelly slain in the Kinslaying at their chief city of Alqualondë, or Swan Harbour. For this reason few or none of the Teleri joined the host of the Valar which set out to capture Morgoth forgood. It is recounted that the Teleri eventually forgave the Noldor for the Kinslaying, and the two kindreds were at peace again.