It all started when a evil man named Zarrko tricked the Thor of the future. The Thor from the future was Dargo. Zarrko tricked Dargo into the past to battle the present Thor. The Thor from the present was Thunderstrike. After they started to fight another Thor appeared. He went by Beta Ray Bill. After Beta Ray Bill stopped the violence he had a solution. They decided to form a group called Thor Corps. Now the team was going to go after Zarrko. Zarrko wanted to become the all master of time. That's when the Thor Corps who at that time were calling themselves hammer brothers went to Zarrko's ship. Many villains were pulled from the time stream to stop the Hammer Brothers including people like Loki and Skurge. But, Loki did not want to be controlled like the others. So he turned on Zarrko which led to his downfall. After that was done Beta returned all the Thors to their original time before the ship exploded.
The Thor Corps was created by Tom DeFalco and Ron Frenz in 1991 and first appeared in The Mighty Thor #440.
The Thor Corps reunited when Demonstaff had Thunderstrike team up with Dargo and got Beta Ray Bill. He did this so they could help find Demonstaff's wife Ellene. Dargo couldn't say no because Demonstaff was holding his wife hostage. If they didn't help find Ellene he would destroy all reality. When they were transported to the place where Demonstaff's wife was the leader Warlord Kargul transported them to World War 2. The Thor Corps were attacked by Captain America and the Invaders. Later they found a portal back to Kargul's world. They then found Ellene but, she did not want to go with them. She said that he just wants to see her die. So later Kargul found out about Demonstaff trying to end all reality. That's when Kargul went to earth to stop him from doing this while Ellene remained on Kargul's world. Ellene then banished all the different Thor Corps members to different timelines. They had to battle Guardians of the Galaxy, Spider-Man, and Kid Colt. They then met back up with each other. Together they summoned the true Thor himself so they could defeat Demon Staff. As the reality began to fall apart Thor used his great powers and stopped the end of the reality. That's when Ellene told him how she felt and he realized he was wrong. So he reversed all of his doings. Since then the Thor Corps have not been together but, they still remember they could be called upon for help one of these days.