Elrond is a great and very wise elf that we
first meet in The Hobbit,in Rivendell. It is 
he that identifies the stolen swords that Bilbo 
and the dwarves find in the Troll's caves, and
it is he that discovers and reads the moon
letters written on the map to Lonely Mountain.  
Later, Bilbo makes for Rivendell after his 
birthday party, very much missing the elves,
and being on the road.  When Frodo is on his
journey, it is Elrond that heals Frodo from his
wound from the Black Riders.  Although Frodo
will never fully recover, he is saved.  It
is in Elrond's house that the elves, dwarves,
and men meet to discuss the fate of the one
ring, and here is where they assemble the
Fellowship of the Ring.  Elrond's daughter is
Arwen Evenstar, and she marries Aragorn after
the War of the Ring.  Elrond, however, sails on
the white ship with Gandalf and Frodo.