During the 1950’s, Timely Comics changed its name to Atlas Publications, and stopped publishing superheroes. Instead, they published comics like Millie the Model (which carried over from the 40’s) and The Two-Gun Kid. After they switched back to superheroes, only three anthologies remained: Journey Into Mystery, Tales to Astonish, and Tales of Suspense. Journey was the first comic to have the Marvel Comics logo (but you can barely tell. It’s just a square with an M and C in it. The more familiar rectangle with the star of the comic would come later), beginning with #69. I actually read a few stories, and enjoyed them. Journey was no Weird Science, but I liked the art.
By #83, sales were slipping. Stan Lee decided their next creation would be a god. They chose Norse mythology because Greek mythology was too familiar. Both Stan and his brother Larry (who often co-wrote when Stan couldn’t meet deadlines) wrote the story.
One thing I’m enjoying about this project is looking at Kirby’s classic art. I now see why he is the King.
Early on, Thor was much different from what he is now. He had the alter ego of Dr. Donald Blake (which he dropped in #159). Loki was introduced two issues later, becoming his main villain. Loki even created three other villains: Absorbing Man, Destroyer, and The Wrecker. Other early enemies included Zarrko, the Enchantress, and Grey Gargoyle. Sif was introduced in #102 (in a flashback, but she’d soon be integrated into the present day), and even though Lee felt Greek and Roman myths were too familiar, Hercules was added as a rival. By #126, Thor took central stage.
Thor became one of the founders of the Avengers, and is still a member to this day. In 2012, he topped IGN’s “Top 50 Avengers” list.
Next: Doom Patrol
Aspie Catholic 
Good summarizing of the history here! I’m not a huge fan of the earliest days of the Thor comic, though I’ve read it. I think from the very earliest days of the title, there was a tension between being somewhat true to the Norse-myth origins of the characters, and yet a need to fit those characters into the superhero-genre mold. These restrictions resulted in Marvel feeling the need to make Loki evil, to give Thor an unnecessary human alter-ego, and to saddle him with adversaries not always drawn from the myths. Now, I’m not thoroughly complaining–while the Simonson era would dip back into Norse mythology, it would also create Beta Ray Bill, whom I deeply love as a Thor fan, but who certainly doesn’t have anything to do with Norse myth. I guess what I’m trying to say is that, from these rather limited beginnings, THOR’s evolution as a comic book title enabled the series to draw more heavily on the Norse traditions while still finding a way for Thor to function effectively as a hero in the wider Marvel universe.