Elrond: Elrond was born around 525 of the First Age, and he was the son of Eärendil and Elwing, and the brother of Elros. His name has been translated in several ways to give very different manners, e.g. 'Star-dome' and 'Elf of the Cave'. He belonged to both the Noldor and the Sindar branches of elves, because his father had Noldorin blood, and his mother had Sindarin.
He was born at the Havens of Sirion, and when the sons of Fëanor attacked, he and his brother were taken captive. However, Maglor took pity on them, and released them. They were found near a waterfall, with Elrond in the cave behind the falls. That is how he got the name 'Elf of the Cave'.
As both his parents were Half-elves, he was given the choice of whether he wanted to be counted with the Elves, or with Men. He chose to be with the Elves (his brother chose the race of Men). At this time he went to live in Lindon with Gil-Galad.
When Sauron invaded Eriador, Gil-Galad sent Elrond to Eregion to help. When Eregion was laid to waste, Elrond retreated into a deep valley with some of the surviving elves. Here he founded Imladris in SA 1697. Rivendell prospered partly because Gil-Galad had given him Vilya, the Ring of Air. He remained Lord of Rivendell until he passed over the Sea.
He fought with Gil-Galad and Elendil in the War of the Last Alliance in SA 3429-3441.
He was wedded to Celebrían in TA 109, but stayed in Middle-earth when she passed over the Sea in TA 2510. She bore him the twins Elladan and Elrohir in TA 130 and Arwen in TA 241.
In the Third Age he was a leader of the White Council, and he advised what was to become the Fellowship of the Ring at the Council of Elrond.
He passed over the Sea with the other Ringbearers on September 29th, TA 3021.