The Silvan Elves were in origin Teleri, and so remoter kin of the Sindar, though even longer separated from them than the Teleri of Valinor. They were descended from those of the Teleri who, on the Great Journey, were daunted by the Misty Mountains and lingered in the Vale of Anduin, and so never reached Beleriand or the Sea. They were thus closer akin to the Nandor (otherwise called the Green-elves) of Ossiriand, who eventually crossed the mountains and came at last into Beleriand.
Elves: the Firstborn Children of Ilúvatar; awoke under starlight on the shores of an inland sea in Middle-earth; invited by the Valar to dwell with them in Valinor, most accepted and set out on the Great Journey to Valinor. Their kindreds were: Vanyar, Noldor and Teleri, led by respectively Ingwë, Finwë and the brothers Elwë (Thingol) and Olwë. The Noldor and some of the Teleri play major parts in The Silmarillion. The remaining Elves, known as the Avari, stayed at Cuivienen.