Loki is one of the Marvel Cinematic Universe's most famous villains. Actor Tom Hiddleston portrayed the character in the Thor and Avengers movie franchises, and the self-titled Disney+ series.
The 2011 movie Thor explains the origin story behind brothers, Thor and Loki. Although Loki believes he an Asgardian, he was born in Jotunheim, home of the Frost Giants. Shortly, after his birth, he is abandoned by his father Laufey. Loki is later taken in by Asgard ruler, Odin.
Although Odin raised Loki as his own son, the latter never felt love or approval from his adoptive father. While Loki had the opportunity to hurt Odin, he refused. Deep down, he cared for the man he called his father. By rejecting the chance to rule Jotunheim, Loki wanted to prove his love and dedication to Odin.
When Loki finally learns the truth about his origins, Loki is angry and wants revenge. Since Laufey was the ruler of Jotunheim, Loki was the next successor to the kingdom. Loki ruling over Jotunheim and continuing the war with Asgard would have been the ultimate betrayal to Odin. Yet, Loki had no interest in becoming leader of his real home, something that has always confused movie fans.
Loki's dream was to be ruler of Asgard once Odin stepped down. However, he knew that Thor, was Oden's favorite and would perhaps ascend the throne. Loki and Thor have always had a sibling rivalry, stemming from Loki's feeling inferior to his brother.
Why did Thor stop Loki from destroying Jotunheim?
With Odin in a deep sleep, Loki takes over as ruler of Asgard since Thor has been exiled. His first order of business is to destroy Jotunheim with the help of the Bitfrost. But his plan is foiled when Thor arrives.
The siblings indulge in a heated battle, with Thor destroying the Bitfrost and Loki falling into a wormhole. Thor knew his brother was using his newfound power for bad rather than good. If Loki had gone ahead with his plan, it would've caused more destruction in the Asgard-Jotunheim War. Although Jotunheim was their enemy, Thor couldn't let the people be killed.
By saving Jotunheim, Thor helped his father Odin's wish of one day bringing peace between the Asgards and Jotunheim.
How did the war between Asgard and Jotunheim start?
The Asgards have been at war with Jotunheim for centuries. When Laufey plotted to conquer the Nine Realms, this forced Odin to declare war. The Asgardians and Frost Giants' vicious battle results in Jotunheim getting defeated. In the process, they took the Frost Giants' most powerful weapon - the Casket of Ancient Winters.
The two sides manage to remain amicable, until the day of Thor's coronation to the Asgard throne. Frost Giants arrive in Asgard to steal back the Casket of Ancient Winters, but are caught by Thor. Unbeknownst to Thor, the Frost Giants were let in by his brother Loki.
Thor, Loki, and a group of Asgardians travel to Jotunheim, where a fight breaks out. Odin is furious when he learns of Thor's actions since this has caused further friction between both kingdoms.
Odin's wish is that one day the Asgards and Frost Giants can live in peace. He plans to use his son Loki to help build a truce. With Loki ruling Jotunheim, both sides have a better chance at ending their long-standing war. However, things don't turn out that way.