Arwen as played by Liv Tyler
Arwen Undomiel (Elvish for Evening Star) is Aragorn's love interest in The Lord of the Rings trilogy
Biography
Aragorn first met Arwen as a young man in Rivendell, one of the last Elvish realms in Middle-Earth. From the moment they met, they fell in love. Arwen's father Elrond reluctantly allowed Aragorn to court Arwen, but would not let them be wed unless Aragorn claimed his role as the king of Gondor.
In the film, Arwen rescues Frodo Baggins from the Nazgul. She then summons a river spirit to drown them, though being undead they would eventually revive. It was also revealed that Elrond was determined to take Arwen with him to the Undying Lands, along with the remaining elves. After convincing Arwen that Aragorn's death would be too much for her to bear, Arwen agrees to go. While on her journey, Arwen has a vision of the child she and Aragorn would have. She then resolves to stay in Middle-Earth, but feels herself slowly fading away. Aragorn has a vision of Arwen dead and solemly marches towards Mordor.
After the end of the War of the Ring, Arwen arrives in Gondor for Aragorn's coronation. The two are finally wed and rule as king and queen. After Aragorn's death, Arwen would travel to the woodland realms and pass away.