Rivendell
Legolas was the only son of Thranduil, King of the Elves of Northern Mirkwood. His exact date of birth and mother's name are unknown.
Legolas came to the Council of Elrond in Rivendell, the great meeting held by the Elf lord Elrond, as a messenger from his father to discuss the escape of Gollum. When the council was choosing the "Nine Walkers" to pit against the "Nine Riders," Legolas volunteered to represent the Elves, and to become one of the members of the Fellowship that would set out to destroy the One Ring.
Aragorn was a descendant of Elros Tar-Minyatur through the line of the Lords of Andúnië to Elendil, High King of Arnor and Gondor. Like all of the kings before him, he was Elrond's kin through the House of Elros.
The war began in SA 1693, almost a century after Sauron had deceived the Ñoldor of Eregion and forged the One Ring, claiming all the Rings of Power from Ost-in-Edhil except for the Three Rings of the Elves.
Elrond was a mighty Half-elf ruler who dwelt in Middle-earth from the First Age to the beginning of the Fourth Age.
Rivendell, or Imladris in Sindarin, was the name of an Elven settlement in Eastern Eriador and the valley containing it. Founded by Elrond Half-elven, it was first a stronghold and refuge in the Elves' first war with Sauron in the Second Age, but in the Third Age became a renowned, peaceful haven for wayward Elves, Rangers of the North, and other travelers.