The Defenders are a loosely-knit band of costumed super-humans who have no official charter or by-laws, no government sanction, no permanent headquarters, and no fixed membership roster. The team began when Doctor Strange, the Hulk and the Sub-Mariner joined forces to battle a common foe, and agreed at the battle's victorious resolution to band together again when appropriate. At first, Doctor Strange was the nexus that brought the team together. Then, the arrival of the Valkyrie became instrumental in keeping the team together on more than a sporadic basis. Due to the unofficial nature of the Defenders, it could be said that any individual who assists the Defenders is a Defender. But, only certain individuals fit the two major criteria of membership:

1.That they consider themselves to be a Defender
2. That they are accepted by the continuing core group as a Defender

The following is a list of the three levels of Defenders membership: The Core Group, The Temporary Members and The Guest Heroes.

The Core Group: These Heroes have met the two criteria for core Defenders classification. Portions of this are still under construction.

Hero Name Occupation First Active Notes and subsequent appearances
Doctor Strange Stephen Sanders (Strange) Master of the Mystic Arts Marvel Feature #1 Founding Member, MF #1-3, DEF #1-on  
Sub-Mariner Namor McKenzie Prince of Atlantis Marvel Feature #1 Founding Member: Quit in Defenders #14
Incredible Hulk Bruce Banner Physicist Marvel Feature #1 Founding Member: Quit in Defenders #17, Rejoins in Defenders #21
Silver Surfer Norrin Radd Former Herald of Galactus Defenders #2 Quit in Defenders #11
The Valkyrie Barbara Norriss (nee Denton) Norse Goddess Defenders #4* aka. Brunnhilda, 
Nighthawk Kyle Richmond Financier Defenders #14-15 Deceased in Defenders #106 (later resurrected)

For origin information, see Defenders #32 (part 2)

Son of Satan Daimon Hellstrom Demonologist Giant-Size Def. #2,  Also in Defenders #24, 25, 33, 62
Red Guardian Dr. Tania Belinsky Neurosurgeon Defenders #35  
Clea Clea Alien Sorceress Defenders #39 Also in Marvel Feature #2,72,102
Hellcat Pasty Walker Housewife Defenders #44 given mind powers by Moondragon in issue #44 got Shadowcloak in issue #60
Devil Slayer Eric Simon Payne Cultist Defenders #57 Uses Shadow Cloak for teleportation
Gargoyle Isaac Christians None Defenders #94  
Beast Henry McCoy Biochemist Defenders #104  
Over Mind Grom Alien Defenders #115 Possessed by Telepaths
Angel Warren Worthington III Businessman Defenders #125  
Iceman Robert Drake Student Defenders #125  
MoonDragon Heather Douglas Priestess Defenders #125  

*Appeared as Barbara Norriss in Defenders #3.

The Temporary Members: The following Heroes participated in Defenders exploits at various times, but were either regular members of other teams or did not remain in the group long enough to become part of the core membership. Portions of this are still under construction.

Hero Name First Active Notes
Hawkeye Clint Barton Defenders #7 Quit in Defenders #11 to pursue solo career
Black Knight Dane Whitman Defenders #4* Quit in Defenders #11 to battle Crusades
Professor X Charles Xavier Defenders #15 Enlisted the Defenders to battle Magneto
Power Man Luke Cage Defenders #17 Actually fought the Defenders in his first appearance. Also Def. #24,25
The Thing Ben Grimm Defenders #20 Member of the FF, help defeat Nameless Ones
Yellowjacket Henry Pym Defenders #23 Ex-Avenger, joins the Defenders to help defeat the Sons of the Serpent
Daredevil Matt Murdock Giant-Size Def. #3 Aided the Defenders against the games of the Grandmaster Also Defenders #24, 25 to defeat Sons of the Serpent
Vance Astro Vance Astrovik Giant-Size Def. #5, Defenders #26-29 Guardians of the Galaxy
Martinex Martinex T'Naga Giant-Size Def. #5, Defenders #26-29 Guardians of the Galaxy
Charlie-27 Charlie-27 Giant-Size Def. #5, Defenders #26-29 Guardians of the Galaxy
Yondu Yondu Udonta Giant-Size Def. #5, Defenders #26-29 Guardians of the Galaxy
StarHawk   Defenders #27-29  
Jack Norriss Jack Norriss Defenders ( ) in cameo, in full ( ), as Defender in Defenders #29 Estranged husband of Barbara Norriss (aka. Valkyrie)
Moon Knight Marc Spector Defenders #49  
Ms. Marvel Carol Danvers Defenders #57 Also attempted to re-join in Defenders #62
Spider-Man Peter Parker Defenders #61 Aided the Defenders in battling Lunatik
Howard the Duck   Marvel Treasury #12  
Wasp Janet Van Dyne Defenders #76  
Aeroika   Defenders #79  
Black Panther T'Challa Defenders #84  
Dracula Vlad Dracula Defenders #95  
Ghost Rider Johnny Blaze Defenders #96  
Man-Thing Ted Sallis Defenders #98  
Wonder Man Simon Williams Defenders #104  
Mr. Fantastic Reed Richards Defenders #105  
Captain America Steve Rogers Defenders #106  
Vision Vision Defenders #112 Also in Defenders #9-11 as Avengers
Scarlet Witch Wanda Maximoff Defenders #112 Also in Defenders #9-11 as Avengers

*The Defenders brought the stone statue of the Black Knight back to Doctor Strange's home in Defenders #4. Issues #5 to #11 dealt with the team's efforts to restore the Black Knight to human form. In the end, the Knight remained in the period of the Crusades fighting along side Richard the Lion Hearted and his "petrified body" remains in Strange's sanctum sanctorum.

The Guest Heroes: These Heroes were guests of the Defenders for one afternoon only appearing in Defenders #62-64, a story arc titled Membership Madness. This portion is still under construction. If you know any Heroes I may have missed, please advise me.

Hero Name First Active Notes
Havok Alexander Summers Defenders #62 Member of X-Men
Captain Ultra Griffin Gogol Defenders #62 Lots of potential and a colourful costume
Black Goliath Bill Foster Defenders #62  
White Tiger Hector Ayala Defenders #62 Uses Sons Of the Tigers amulets
Iron Fist Danny Rand Defenders #62 Heroes For Hire
Falcon Samuel Wilson Defenders #62 Former partner of Captain America
Jack of Hearts Jack Hart Defenders #62 Space traveler
Torpedo Brock Jones Defenders #62 Torpedo III, enemy of the Dire Wraiths
Stingray Dr. Walter Newell Defenders #62 Last fought the Hulk in Hulk #221
Prowler   Defenders #62  
Tagak   Defenders #62  
Nova Richard Ryder Defenders #62 Lost his powers in ROM #24
Polaris Lorna Dane Defenders #62 Reserve member of X-Men
Marvel Man Wendell Vaughn Defenders #62 Now goes by the name Quasar
Hercules Hercules Defenders #62 Olympian, voted to head Defenders
Paladin Unknown Defenders #62 Mercenary/Private Investigator

If you notice anything which you suspect may be incorrect, please advise me by email HERE.

Most of this information is taken from The Official Handbook of the Marvel Universe #3 (C-D) March 1983.