When Melkor repented and feigned loyalty to Manwë, he was released from the Halls of Mandos. Afterword, Feanor, crafted the Silmarils and the jewels were coveted by Melkor. Melkor approached Feanor for the Silmarils but was dismissed by him.

After the slaying of the Two Trees, Melkor with Ungoliant came upon Formenos to plunder its treasures. Melkor, now trapped in his tyrant of Utumno form, slew Finwe, King of the Noldor. After killing Finwe, Morgoth plundered the treasures of Feanor and stole the Silmarils and other jewels as well. This act would be what would start the War of the Jewels.
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