Silvan Elves (also known as Woodland Elves) are described as being less wise than other Eldar, and some of them almost are indistinguishable from the Avari, those who never joined the Great Journey from Cuiviénen to Aman.
The Silvan elves were notably of Nandorin background and descended from the followers of Lenwë who were fascinated by the landscape and its features of the lands East of the Misty Mountains, and followed the Great River down into south and beyond. Many centuries later, they reappeared and spread themselves throughout the regions between the Misty Mountains and the Blue Mountains. Later yet, they appeared in the Beleriand under the leadership of their only king Denethor and were allied to Thingol, the elven King of Doriath. When Morgoth attacked Beleriand, Denethor was killed and his people suffered heavy causalities and later became a secretive people throughout the rest of the First Age.
When the Beleriand was lost and the Second Age was to begin, the Silvan elves who survived rejoined their kindred east of the Misty Mountains and gradually became citizens of the Elven realms of Lórien and Greenwood the Great (later northern Mirkwood), or were at times wanderers. There is also the fact that Legolas Greenleaf, son of Thranduil, is a Silvan Elf and the Prince of Mirkwood.