Oropher was the father of Thranduil, who was known as the "Elvenking" in
The Hobbit, and grandfather of Legolas.
2
He was initially the "King of the Silvan Elves east of Anduin".
3 When Oropher retreated northward in Greenwood the Great he became known as "King of the Elves of Greenwood the Great".
2, 4 Although a Sinda himself, Oropher ruled over mostly Silvan elves.
3
He died in the first assault upon Mordor in the War of the Last Alliance. His son, Thranduil, survived and succeeded him as king.
2
Positions & titles
King of the Silvan Elves east of Anduin - King of the Silvan Elves of Greenwood the Great - S.A. 3434 References
1 - J.R.R. Tolkien, Christopher Tolkien (ed.), Unfinished Tales, The History of Galadriel and Celeborn, Appendix B: The Sindarin Princes of the Silvan Elves
2 - J.R.R. Tolkien, The Lord of the Rings, Appendix B, The Second Age
3 - J.R.R. Tolkien, Christopher Tolkien (ed.), Unfinished Tales, The Disaster of the Gladden Fields, Note 14
4 - J.R.R. Tolkien, Christopher Tolkien (ed.), Unfinished Tales, Index