Thranduil, the father of Legolas, first appeared in the Hobbit book simply as "The Elven King" with no mention of his real name. Is it only in The Lord of the Rings, when Legolas first appears in the books, that he is identified as the Son of Thranduil of Mirkwood. When Legolas enters Lothlorien in The Lord of the Rings: The Fellowship of the Ring , Haldir greets him in Elvish as "Legolas Thranduillion."