Later, the Second White Council was held in Rivendell, where Gandalf attacked the Fortress of Dordogo in 2851, as Sauron was stationed there disguised as a Necromancer. Third, Saruman did not agree to do so. Interestingly, this action has been delayed for a long time. It was not until nearly a century later, in 2941, that the White Order decided to launch an attack on Dordo, and in 2941 Gandalf, Bilbo Baggins and the Dwarven Thorin arrived at Rivendell. They settled here briefly, after which they continued on their journey to defeat Smaug and regain lonely mountains. During his time at Rivendell, Elrond showed the dwarves the secret of the moonlight letter that opened the gates of Erubeau. One of the reasons Gandalf advocated the expedition was that he feared that Sauron would use Smug to wreak havoc in the North, or to condone Smuger's attacks on the Valley and Rose Royron. After successfully completing the expedition, Gandalf and Bilbo passed by Rivendell on their way home and stayed there for a while.
In 2933, at the age of two, Aragon became the 16th dunedan chief, and Elrond adopted him as his adopted son. Aragon lived in Rivendell until the age of 20, when he met Elrond's daughter, Alwei, and the two fell in love. Throughout his long journey through Aragon, Elrond has been his homecoming. Later, during the Lord of the Rings Jihad, Elrond sent Groverdale to find Aragon and the four hobbits and take them safely to Rivendell.
In 3002, Bilbo settled in Rivendell, where he lived until 3021 A.D., and wrote a first-age history, The Principles of Elven Translation (in the Red Book of the Western Frontier), drawing on documents from the Valley Collection. In September 3018, Frodo Baggins left Charles with the Ring and headed for Rivendell, where Nazgur chased him. On 20 October they passed the Port of Bruynen, Elrond summoned the river to rise and washed away the Nine Commandments. On 25 October, Elrond met in Rivendell to discuss the treatment of the Lord of the Rings. Many people attended the meeting, brought all sorts of news, and sought advice, including Legolas of the Black Forest, Groin and Jimley of the Lonely Mountains, and Polomer of Gondor, who learned from his dreams that the fragment of Nasir's sword was in Rivendell. Frodo volunteered to go to Mordor to destroy the Ring, and the meeting also elected 8 members to form an expedition to accompany him. The elven craftsmen of Rivendell reforged Nasir, which Aragon named Andulier. On 25 December, the expedition departed Rivendell.
During the Lord of the Rings Holy War, Elrond's elven ring begins to fade, and Rivendell's power begins to wane.
After Sauron was defeated, Elrond decided to leave Middle-earth. In September 3021, he and Bilbo left the valley and sailed west from Grey Harbor. During the Quaternary Era, Merry Brandy visited the valley several times to gather information to compile the Chronicle. Elrond's sons, El radan, el-Hill, stayed in Rivendell for a while, and their maternal grandfather, Kellerborn, moved in with them. Kellerborn eventually left Middle-earth, but no one knows if El Radan and Ellohir also left. One message suggests that Rivendell was also abandoned after Aragon's death in 120 Argonauts.
Rivendell has always represented the culture of the elves, whether in the halls of fire or in the prairie, the sun and the stars under the woods, and Tolkien has a relationship with Rivendell when he mentions these skills, where you can see a lot of elven cultures, such as Sinda and Nodo. Rivendell is not a place where wars often break out, but rather a place to remember, it is a warm home east of the sea.