Jotunheim is one of the Nine Realms of Yggdrasil and the homeworld of the Frost Giants. Jotunheim is a dark, icy world in a distant part of the Marvel Cinematic Universe. Jotunheim's ruler was Laufey before he was murdered by Loki Laufeyson.
Jotunheim is first seen during the first war with Asgard, where it is seen devastated by the war and surrenders to the Asgardian king Odin.Over a millennium later, in the twenty first century, Jotunheim is still devastated by the war. Thor, Loki, Sif and the Warriors Three trespass Jotunheim to question Laufey as to how three Jotunns entered Asgard in a failed attempt to steal the Casket of Ancient Winters. Laufey insists that an Asgardian granted his soldiers access into Asgard. When Thor fights with the inhabitants of Jotunheim, Laufey threatens a declaration of war, resulting in Thor's banishment from Asgard. It is later revealed that Loki is Laufey's son, taken from Jotunheim and adopted by Odin. When Loki becomes the Regent King of Asgard is in Odin's position, he reveals that he allowed the Jotunns into Asgard to stop Thor from being pronounced king. Loki forms a pact with Laufey that will let Laufey kill Odin in his sleep, but Loki betrays and kills Laufey before he can do so. Jotunheim is partially devastated when Loki uses the full power of Bifrost to try and destroy Jotunheim, before the now changed Thor saves the race by destroying the Bifrost, and in doing so destroying Asgard's only means of interplanetary travel.