Loki was born in Jotunheim as the son of Laufey. However, when Odin drove the Frost Giants back into Jotunheim, the All-Father kidnapped Loki and raised him as his son, hiding his heritage. Loki's confusion over his fatherhood and deeply ingrained hate of Asgardians even though he was one led to him becoming insane. Loki secretly had his brother Thor exiled and convinced him, through lies and deceit, not to return. He also sent the Destroyer to Earth to "destroy everything" out of pure malice. Loki planned to use the bifrost bridge to destroy Jotunheim, proving himself worthy to Odin. When his plan was foiled, Loki apparently killed himself by letting go of his adoptive father's hand and falling into the abyss. However, Loki survived, though it is unknown how: he was seen in the post-credits scene of Thor, expressing interest in the Tesseract.
Loki later wields the Chitauri Scepter, gifted to him by Thanos, and wages a war against Earth in the Avengers. He is eventually defeated by the Avengers and is transported back to Asgard using the power of the Tesseract with Thor, where he is locked up in an Asgardian dungeon.