Elves of the forests of Middle-earth
The Silvan Elves is the name of the groups of Elves who inhabited the forests in the eastern parts of Middle-earth, specifically [[Mirkwood] and Lothlórien. They are also called Wood-elves.
The Silvan Elves have their origins as a mix of several clans of Elves that settled in the Vales of Anduin - Sindar, Nandor, Teleri and Avari - those of the elves who heard the call of the Valar and began to travel to Valinor but did not complete the journey, and instead remained behind in Middle-earth. Led by their leader Lenwë, these elves did not cross the Misty Mountains and instead settled around the Anduin River.
The language of the Silvan elves was called Nandorin, and fell out of use during the First Age, being replaced by Sindarin. Nandorin only remains in some ancient place-names such as "Laurelindórinan", the old name for Lothlórien.
There were few High Elves left in Middle-earth after the fall of Beleriand, and far fewer still that left Lindon to settle in the East, so these did not make up a significant portion of the Silvan Elves - but Galadriel is one among them. As a High Elf, rule of the Golden Wood fell to her when King Amroth died childless.
The other rulers of the Silvan Elves belong to the Grey Elves, or Sindar. These include Oropher, Thranduil and Legolas of the Woodland Realm, and Amdír, Amroth and Celeborn of Lórien.