|Battle of the Thousand Caves|
|Conflict: The War of the Jewels|
|Date: FA 503|
|Place: Caves of Menegroth|
|Outcome: Dwarves of Nogrod are victorious|
|Elves of Doriath||Dwarves of Nogrod|
|Elves of Doriath||Dwarves from Nogrod|
|Other Battles of Beleriand|
Battle of the Lammoth - Battle of the Firth of Drengist - Glaurung's attack on the Beleriand - Battle of the Thousand Caves - Battle of Sarn Athrad - Battle of Tumhalad - Second Kinslaying - Fall of Gondolin - Third Kinslaying
After the Quest for the Silmaril and the Hunting of the Wolf, Thingol came to possess the Silmaril that Beren cut from Morgoth's Iron Crown. Then around FA 500, Hurin, freshly released from his long imprisonment by the Dark Lord appeared and presented to the King the Nauglamir that he took from Mîm at Nargothrond. Seeing that he now possessed the two most beautiful things ever created by the Children of Ilúvatar, Thingol desired to combine them into one great creation. From this, he contracted the Dwarven craftsmen working in his smithies who were strongly motivated because the Nauglamir was a creation of their own race, and they too desired the Silmaril but hid it well.
Long did they labor in the deep smithies of Menegroth and when the marvelous creation was complete, King Thingol came to claim it but the Dwarves coveted it and withheld it from him saying he had no right to it. Seeing their true minds, Thingol scorned the Dwarves with hurtful words in praise of himself. Then, the Dwarves unable to bear anymore rose before him and slew him then and there took the Nauglamir and the Silmaril within it and fled. The killers managed to get out of Menegroth but not out of the realm for word quickly spread on who was responsible and the Dwarves were pursued to the death. Most of them were killed and the Nauglamir and Silmaril returned to Doriath. Only two Dwarves escaped. Melian, unable to bear the loss of her husband and seeing that that the doom she had so feared had finally come upon Doriath withdrew her protection, and entrusted Mablung to send word to Beren at Tol Galen and gave him the Silmaril for safe-keeping. She then left Middle-earth and returned to Valinor.
The surviving Dwarves that made it back to Nogrod when asked what happened they lied to their Lord saying that their brethren were slain on the command of Thingol, who intended not to pay them for their works. The Dwarves quickly became wrathful intending to avenge this wrong. They were trying to get the Dwarves of Belegost to help but they refused and also tried to dissuade them from their intent, but they did not succeed. The Dwarves assembled a great host and marched westward through the Beleriand. All trembled at the host of the Dwarves therefore when they passed through the now unguarded borders of Doriath, no one opposed them and retreated before them. Then, the host came to Menegroth, crossed the Bridge of Menegroth and entered the caves and so the battle begun.
The battle took place entirely underground in the many thousands of the Caves of Menegroth. It is not known how long the two foes fought one another only that many died on both sides but the Dwarves emerged victorious. The battle remained in the racial memories of both Elves and Dwarves for many ages to come.
After the Dwarves won the battle, they pillaged and plundered all they could and then eager to get their hands on the Nauglamir and the Silmaril, they came to the treasury of the realm and slew Mablung before its doors taking both the treasures. Doriath was sacked but the Dwarves did not occupy the realm and instead left for home. Doriath ceased to be without the King or his Queen. Even Beren's avenging of the defeat at Sarn Athrad did not resurrect the kingdom, not until the coming of age of Beren's son Dior.