Isildur is first met by High Elf characters during the battle at Dagorlad at the end of the second age.
In Númenor it was Isildur who discovered the treasury of King Ar-Pharazôn (which lead to the Downfall of Númenor and the reshaping of Arda) and he decided to steal a fruit of Nimloth, the White Tree of the Eldar, and so save it from destruction. In II 3319 all of Elendil's family managed to escape Númenor in several ships, but in a great storm the ships were departed and Isildur and Anárion landed in Gondor, while Elendil landed to the west and soon founded the Kingdom of Arnor.
While Isildur settled in Minas Ithil, his younger brother Anárion settled in Minas Anor. The two jointly founded and ruled the Kingdom of Gondor out of Osgiliath, though later Elendil became the official High King over both realms. Anárion had one son, Meneldil.
In II 3429 Sauron overtook Minas Ithil but Isildur managed to escape with his family to Annúminas, where his father dwelt. Isildur marched on with the great host in "The Last Alliance of Elves and Men" and they managed to overtake Barad-dûr after a seven year long siege, during which his brother was slain. In the final battle (II 3441) Elendil was slain and Narsil broke. It was at that crucial moment that Isildur took the hilt and cut off the One Ring from Sauron's hand.
After these events Isildur returned to Gondor and rebuilt much that was broken. He set Meneldil, Anárion's son, to govern the land. After having buried his father at Amon Anwar he departed for the long journey home together with his adult sons and many strong guards. However, he wanted to pass by Imladris (Rivendell) to bring with him his wife and youngest son. Sadly they were ambushed by ten times as many orcs and badly defeated in what is known as the Battle of the Gladden Fields.
Realizing the grievous outcome Isildur sent Ohtar and his companion to at all costs bring Narsil into safety. It is until today stored in Rivendell.
Next happened the next crucial event in the tale of the One Ring, when he listened to advice of Elendur, his son, and put on the Ring:
- "Isildur turned west, and drawing up the Ring that hung in a wallet from a fine chain about his neck, he set it upon his finger with a cry of pain, and was never seen again by any eye upon Middle-earth." — Unfinished Tales, by Tolkien
Almost all of his host was slain. Isildur escaped almost unnoticed, but Orcs has a superhuman smell and followed his trail. Eventually he swam over river Anduin but the Ring fouled him and slipped off his finger to the depths below, he became visible and was shot by orcs, and he fell into the water and was never found.
So it happened that Isildur, Elendur, Aratan, and Ciryon all died in Third Age 2; and Isildur ruled as High King of Arnor and of Gondor for only two years. Now only Valandil, Isildur's youngest son, remained to rule as High King of Arnor, while Meneldil became High King of Gondor.
|Birth - Death||Second Age 3441 - Third Age 2|
|Child(ren):||Elendur, Aratan, Ciryon, Valandil|
|Info:|| Younger brother: Anárion|
The two founded Gondor but gave sovereignty to Elendil, their father.
- The Silmarillion, by Tolkien
- Unfinished Tales, by Tolkien
- The Lord of the Rings, by Tolkien