So Marvel Feature #1 involves Dr. Strange getting a mystic SOS. so he summons Hulk andSub-Mariner. Together, they beat the villain in just one issue and all go their separate ways.
Then, Marvel Feature #2 involves Dr. Strange getting kidnapped by Dormammu. So Clea she mystic SOS and summons Hulk andSub-Mariner. They beat Dormammu in one issue and all go their separate ways.
Then, Marvel Feature #3 involves Jim Wilson watching the filming of a TV show where something goes mystically wrong, so he asks Dr. Strange for help. Hulk comes along and Strange summons Sub-Mariner for help.
At the end of this issue, Sub-Mariner tells Dr. Strange to lose his phone number. And Hulk says he doesn’t want to be on a team.
The villain above, Xemnu, was the first Hulk.
It was in two Lee/Kirby issues of Journey to Mystery. Xemnu hasn’t been seen since. But he’ll be a fairly regular foe of The Defenders.
At this point, they get their own comic–Defenders #1.
Creators: Roy Thomas and Ross Andru
For the complete history of the MU, year by year, go here.