Thor (Dr. Jane Foster)Created by Stan Lee & Jack Kirby (Journey into Mystery #84)
After Thor became unworthy following a battle on the moon with Nick Fury, his hammer remained there until it was claimed by an unknown woman who became the new Thor. After learning of an alliance between Malekith and The Frost Giants, the new God of Thunder intervened but was challenged by the unworthy Thor, who demanded she relinquish the hammer.
The two would team up to defeat the villains, and the unworthy Thor took the name Odinson, granting the title of Thor to the woman who carried Mjolnir. This did not stop him investigating who in his life this new Thor could be, as Thor herself became more invested in the goings on of the Roxxon Corporation and their CEO, Dario Agger.
When Odin sent The Destroyer to bring back Mjolnir, All-Mother Freyja used Odinson’s list of likely candidates to draft an army of super-heroines to aid Thor in her battle. After the fight, Thor returned to Asgard, where it was revealed she was none other than Dr. Jane Foster, who had been living there as a member of the Congress of Worlds while she underwent treatment for breast cancer.
Every time Jane transformed into Thor, it would wipe away all progress made by her chemotherapy, yet that never deterred her from wielding the hammer, as there must always be a Thor. She was one of the few people from Earth-616 to make it through to God Doom’s Battleworld, and rallied the Thors in revolt against him,. When reality returned to normal, she continued in her attempts to bring down Roxxon.