Although very little is known about the identity of Legolas' mother, she is referenced a few times in The Hobbit films, and a big part of the source of contention between Taurial and Thranduil is that she thinks him cold and unfeeling, and he thinks her naive and foolhardy.
Legolas' father, the Elven king Thranduil, is fond of Tauriel, and "sees something very special in her", though she understands that Thranduil would not approve of her pairing with his son, which Thranduil confirms in The Desolation of Smaug when he tells her not to give Legolas false hope of such a relationship.
Their relationship is fraught with awkwardness thanks to Tauriel's solely platonic feelings toward Legolas. Despite the unrequited interest, the two Mirkwood Elves have a great deal of respect for one another and have each other's backs. Legolas also comes to accept that Tauriel does not see him the way he sees her.
Thorin sees them and asks for help, but Thranduil, realizing that he would just be leading his soldiers to their deaths, refuses, not wanting to risk the lives of his kin, causing Thorin to develop a strong dislike of the Elves.
It is believed that after Kili dies, Tauriel becomes a lone rider and never loves again, she was so broken by the experience of losing him. Their love was real, and it was as strong as any other Middle Earth romance story. But this romance doesn't appear in the original book, so where did it come from?
While Thranduil didn't have a problem with Dwarves, he didn't care for a lot of Elves. In the book, Thranduil was an isolationist and with good reason. Thranduil was a Sindarin Elf, which meant that he had never been to Valinor, and he grew up in Doriath under the leadership of King Elu Thingol and Melian the Maia.
Movie version. Because Thranduil knew that if he aided the Dwarves then he was taking the risk of Smaug retaliating and burning Mirkwood to ashes. Also he knew the Dwarves would just try return to Erebor and attack Smaug.
From the information above, I would say that Thranduil preferred to keep himself at an arm's length from Elrond and Galadriel, the two most prominent Noldor remaining in Middle-earth; they would be on civil but not warm terms.
Tauriel truly threw a wrench in Legolas' life when he fell in love with her. She was brave, fierce, and a protective leader of the guard. He was meant to be the dutiful son of King Thranduil, but in loving her, he became a stubborn, masterful archer instead. He loved exploration and adventure over his duties.
Legolas does not marry or have any children, based on the appendix of The Lord of the Rings. Regardless of who his mother was, Legolas is the last of his line. When he sails into the West at the beginning of the Fourth Age, he leaves no family members behind.
However, a specific scene in The Lord of the Rings has led fans to theorize that Frodo and Legolas didn't talk, not because of time, but because the hobbit didn't know Legolas' name (and was too embarrassed to ask).
Thranduil adopted her when her parents were slaughtered by Orcs and Legolas is like a brother to her. Unlike Legolas, she doesn't hate dwarves and finds some attractive. She wishes to avenge her parents death on the orcs and is a brilliant fighter.
Aragorn and Legolas are long-time companions and best friends since Legolas' father Thranduil sent him to live among the Rangers of the North. Aragorn and Legolas grew close, up to the point where Aragorn revealed his true identity to Legolas. Throughout his journeys, Aragorn and Legolas are as close as brothers.
Early life. Born in TA 2341 of the Third Age, Tauriel was the daughter of Tauressar and Calmiriel. During that year when she was born, her parents went on a scouting mission to the southern borders of Mirkwood until they were ambushed by Orcs that probably spawned from the old fortress of Dol Guldur.
The White Gems of Lasgalen were made by the Dwarves of Erebor for Thranduil to give to his wife initially. During the Greenwood - Angmar war, she was captured and taken to Angmar by Orcs, where she was killed.
So, Thranduil would have seen and experienced some awful things before the Valar, Eärendil and the Great Eagles overcame them. Thus, even though Tolkien didn't record Thranduil's involvement with dragons, it makes perfect sense that he would have seen and been burned by them.
Sauron sent an army to attack King Thranduil, as well as Dale and Lothlorien. King Thranduils son was a member of the fellowship. He helped indeed. If you're wondering why he didn't send his army to the aid of Minas Tirith, he knew Sauron was going to attack his home, and Sauron did just that.
Mentioning his past, Thranduil is portrayed as a widower and also an isolationist king who isn't concerned with the evil that happens beyond his borders. He has generously raised Tauriel for the last 600 years, and also mentions that he has fought the "serpents of the North".
When meeting with Thranduil, Thorin says, “Imrid amrâd ursul” – “Die a fiery death.” When Thorin then recounts the meeting to Balin from his prison cell, he states that he told Thranduil “to 'Ishkh khakfe andu null'” – “pour my excrement on his head.” Another dwarvish insult came from Gimli in The Fellowship of the ...
Tolkien never specifies what became of Thranduil past a certain point -- whether he stayed in Middle-earth or left for the Undying Lands like much of his kin. Though his realm stayed strong well into the Fourth Age, only the fate of his son is known.
Tauriel admits her love for Kili in The Hobbit: The Battle of the Five Armies. Tauriel leaves Thranduil and accompanies Legolas and Bilbo to Ravenhill in order to warn Thorin, Dwalin, Fili, and Kíli of an upcoming attack led by Bolg.
