Title: As Kind as Summer
Personal Website: Paranoidangel
Elrond, although not seemingly a major character in any of the books, does appear in The Silmarillion, The Lord of the Rings and The Hobbit. There are more details about his life in the Appendices and yet there are still many gaps. Often all we have is a date and an action, which makes deciphering his personality somewhat difficult. It also leads to many different interpretations, so in this essay I will tell you how I see him and what it is about Elrond that makes him so interesting.
Elrond is known as Peredhil which means Half-Elven. His parents, Eärendil (father) and Elwing (mother), were half-elf, half-man, therefore so are Elrond and his brother Elros. They were born sometime towards the end of the First Age and while they were still children the sons of Fëanor came looking for the Silmaril, which was a jewel in Elwing's possession. Eärendil was at sea at the time and Elwing escaped with the Silmaril. Elrond and Elros's lives were spared by Maglor - one of Fëanor's sons:
"For Maglor took pity upon Elros and Elrond, and he cherished them, and love grew between them..."
(Of the Voyage of Eärendil, The Silmarillion)
Sadly, though, this is all we know of what happened during that time, so it is impossible to say exactly how Elrond felt about all of it.
At the end of the First Age, Elrond and Elros are given a choice: to be counted among the elves or the men. Elrond chooses elves and Elros men. Elros goes on to be king of a new land, Númenor, marry and have children. We have no way of knowing whether the brothers saw each other or even communicated before Elros's death in 442 Second Age. At this point Elrond has lost all of his close family, and Elros's are more like distant relatives to him.
Elrond begins the Second Age living with Gil-galad who was High King. There was undoubtedly some affection between them, for Gil-galad makes Elrond his heir, even though they were only distantly related. Gil-galad's death at the end of the Second Age is a blow for Elrond as it once more leaves him with no family, and he refuses to take up the kingship.
By that time Elrond is Lord of Rivendell, which he founded to be a refuge from the war taking place in the rest of Middle-earth against Sauron. Elrond is also Gil-galad's standard bearer and is showing himself to be a leader, much like his brother in that respect. Rivendell continues to be a haven for many years and Elrond takes in many different species, including elves, men, dwarves and hobbits.
It is sometime during the Second Age that Elrond meets his wife, Celebrían, when she comes to Rivendell with her mother:
It was then that Elrond first saw Celebrían, and loved her, though he said nothing of it.
(History of Galadriel and Celeborn, Unfinished Tales)
He must have told her at some stage because they marry in 109 Third Age. Twenty years later their sons Elladan and Elrohir (who are identical twins) are born. A hundred years after that they have a daughter, Arwen. For an immortal race this all happens within a very short time, which suggests to me that Elrond desperately wanted a family, perhaps in part to replace the one he had lost. For a while, Middle-earth is at peace and he has time to devote to them - time which he was unlikely to have had in the Second Age.
However, because this is Elrond we are talking about here, this brief period of happiness does not last very long. Celebrían is attacked and Elrond, who by this time is less of a warrior and more of a renowned healer, is only able to heal her physical wounds. Instead, she departs over the sea and Elrond stays in Middle-earth. We know this whole event affects Elladan and Elrohir deeply, and doubtless Arwen too, but of Elrond we know nothing.
He can be reasonably sure he will see her again but their parting cannot have been an easy one. The reason for him staying in Middle-earth until the end of the Third Age must be his duty to Middle-earth. He knows the One Ring has been lost, and Sauron is regrouping and trying to wipe out the line of Chieftains, which Elrond had begun to foster in the late 2100s (the Chieftains being displaced kings and direct descendants of Elros). Sadly, the text says nothing more than this. So we have no way of knowing how much time the Chieftains spent in Rivendell, or how Elrond felt about them.
The last Chieftain and his relationship with Elrond is the one we know most about: Aragorn. His father was killed when Aragorn was only two years old, so for safekeeping, lest the line die out, Elrond takes Aragorn and his mother into Rivendell.
"...Elrond took the place of [Aragorn's] father, and came to love him as a son of his own."
(The Tale of Aragorn and Arwen, Appendix A, The Lord of the Rings)
Aragorn is different from all the other Chieftains because he falls in love with Arwen (and from the description of her you can't blame him) and eventually she loves him too. This leads to Arwen deciding to forsake her immortality - the children of Elrond having been given the same choice as him.
Elrond tries to talk Aragorn out of it, and in the end gives him an ultimatum - he cannot marry Arwen until he is King of Gondor and Arnor. Other than that he does nothing else to stop their marriage, although the temptation must have been great. In the film version of The Two Towers Elrond manages to send Arwen away, and I have no doubt he considered the possibility. But she is, after all, his daughter and her happiness ultimately means more to him than her life. Similarly, he thinks of Aragorn as his son and probably cannot deny him either. He knew the possibility of any of his children making this choice before they were even born, but knowing this is not the same as it actually happening.
After the War of the Ring, at the end of the Third Age, Aragorn and Arwen are married. Elrond is understandably upset about this. He leaves over the sea to join his wife, partly because he misses her and does not wish to see Arwen die. However:
"...grievous among the sorrows of that Age was the parting of Elrond and Arwen..."
(The Tale of Aragorn and Arwen, Appendix A, The Lord of the Rings)
When Elrond departs he leaves all of his children behind. Elladan and Elrohir delay their decision for a while and there is no way of knowing for certain whether they join their parents or follow Arwen's choice into mortality.
There is so much sorrow in Elrond's life - throughout it he loses nearly all of his family, some forever, some for a shorter time. Yet even though Elrond is so often faced with the deaths of those he loves, he still sets himself up for more. He fosters the Chieftains, loving the last of them like a son, even knowing they will die, sooner or later. Perhaps this is indicative of Elrond's personality: he cannot stop helping people. Which is what makes Rivendell the place it is. Bilbo Baggins, although having stayed there only briefly, is certain that Elrond will take him in, which, of course, he does.
Everything that Elrond goes through could have broken a lesser person, but it does not seem to outwardly change him:
"He was as noble and fair in face as an elf-lord, as strong as a warrior, as wise as a wizard, as venerable as a king of dwarves, and as kind as summer."
(A Short Rest, The Hobbit)
Which does make him sound perfect but he is not. His weakness, along with being his strength is that he loves deeply. That is why he is able to lose so much - had he not married Celebrían he would not have had to go through the pain of losing her or Arwen. But then he would not have had the joy of a family either. This is what, for me, makes Elrond such an interesting character. The questions which we do not have the answers to are how much can he lose and how much will he bring upon himself for love? Would he never love again or would he always find others who need him?
It is difficult to sum up the life of a person who lives 6000 years, so I have mainly given the parts that concern Elrond directly, rather than the ones that affect Middle-earth only. Although Elrond was certainly important in its history:
"Elrond is an important character, though his reverence, high powers, and lineage are toned down and not revealed in full."
(Letters 131, referring to The Hobbit)
There is more information about Elrond in The Encyclopedia of Arda and in the Henneth Annûn Resources section (although you have to be member to access it). I have also simplified many events to avoid lengthening this essay by explaining them but you can also get more information on anything I have mentioned here at these places.
The best way to learn more about him as a character, and of others interpretations is through fanfic, although as he is married, many of them are het. If you go to Henneth Annûn or Stories of Arda and search for Elrond that is a good place to start. I also have a few that I think give good insights into Elrond and his relationships with others (and I like them):
History Lessons and History Lessons: The Second Age by Nilmandra
Elrond's life and other events during the First and Second Ages
Choices by Vorondis
Elrond and Elros's choice
The Spectre at the Feast by jessicaramage
Elrond and Elros after the choice
Reminiscent Threnody by AfterEver
Elrond's choices and his relationships with others
Sapphire Aurae by Bejai
Elrond and his relationship with his wife and ring, Vilya
As Kind as Summer by snowballjane
Elrond's relationship with Vilya at the end of the Third Age
A Tale of Elrond and Celebrían by Nemis
Elrond's relationship with his wife, and with Gil-galad
Elrond's Boys by Dragon
Elrond's relationship with his sons
A Bitter Gift by Avon
Elrond and (young) Aragorn
Bitter Parting by GreyLadyBast
Elrond and Arwen
Bearer of Bad Tidings by LOTR lover
Elrond and his relationship with Arwen in the Fourth Age
If anyone wants to challenge any of the opinions I gave in this essay, or put forth any of their own, then I would love to hear what you think.