SindarIn the works of J. R. R. Tolkien, the fictional Sindar (meaning Grey People) are Elves of Telerin descent. They are also known as the Grey Elves. Their language is Sindarin.
The Teleri were the greatest host of the Eldar. They had two kings, the brothers Elwe Singollo (or Elu Thingol in the Sindarin tongue)and Olwe. When the Teleri reached Beleriand during the great march from Cuiveinen, Thingol went wandering in the forests as was his wont. In the forest of Nan Elmoth he met Melian, one of the Maiar of the race of the Valar. They fell in love and with Melian Thingol stood spellbound in Nan Elmoth for several years. In the meantime, Olwe and many of the Teleri grew impatient and went to Aman without him. The rest of the Teleri stayed in Middle-earth to search for their king. At long last he awoke from the spell and set up a kingdom in Beleriand. After the arrival of the Noldorin exiles, the activity of Morgoth's forces increased and Thingol had Melian use her magic to create a girdle of bewilderment around their lands, so that nobody could enter without the king's permission.
Doriath (Land of the Fence), as the land came to be called, developed a civilisation all its own and Dwarves were contracted to aid in the building of the city of Menegroth (the Thousand Caves). That civilisation also developed its own language - Sindarin. Sindarin was known as the Noble Tongue, and became the Elvish tongue used in daily speech throughout Middle-earth. It even replaced Valinorean (Quenya) as the language used by the Noldor in Beleriand, even in Noldorin settlements such as Gondolin. It was passed down through the ages and even survived the Downfall of Númenor; the Númenórean nobles of the House of Elendil brought it to the Realms in Exile (Arnor and Gondor) and there it became an inherited language for the more respectable citizens.
For more information, see The Silmarillion.
An excellent resource for Sindarin can be found at: http://groups.msn.com/laurelindorean