The first Legion of the Unliving was brought forth by Kang who used a machine created by Immortus
to summon together a group of warriors. Choosing to rely on those from the past who had since died to serve him in his quest to capture the Celestial Madonna, Kang's recruits included Baron Zemo, Frankenstein's Monster, the Ghost, the original Human Torch, Midnight Sun and Wonder Man.
The Legion of the Unliving was created by Steve Englehart, Sal Buscema and Joe Staton in 1974 and first appeared in The Avengers #131.
The Legion of Unliving have reappeared several teams usually led by a different villain and often featuring a different roster entirely. Following Kang's Legion of the Unliving, a second team was assembled by the Grandmaster, a third by Immortus and a fourth and fifth by Grim Reaper. Of the various teams, Swordsman holds the record as most frequent member of the Legion having served in three different incarnations of the Legion of the Unliving. One of the recurring ironies is the fact that very few members of all different line-ups have remained dead, many being revealed to actually have been alive, bringing their association with the team into question.
Major Story Arcs
Celestial Madonna Saga
When Kang sought to marry the Celestial Madonna, the Avengers swore to protect her so Kang assembled the first Legion of the Unliving to destroy the Avengers on his behalf. Kang trapped the Avengers inside a castle laced with concrete labyrinths and send his six slaves of death to eliminate them.
As the Avengers fought against different members of Kang's Legion, Kang's plans fell apart when both the Human Torch and Wonder Man instead switched sides and fought against Kang alongside the Avengers. It was also due to Kang's usage of the original Human Torch that the Vision learnt of their connection.
Contest of Death
Several years later the Avengers and the Silver Surfer were abducted by Grandmaster who had captured Death and created five life bombs that were capable of destroying the universe. The Grandmaster forced the heroes to play in one of his contests in order to save the universe. Initially set against each other, in a later round the Grandmaster pitted the heroes against his own Legion of the Unliving. Grandmaster's Legion included Baron Blood, the original Black Knight, Bucky, Captain Marvel, Death Adder, Dracula, Drax the Destroyer, the Green Goblin, Hyperion, Nighthawk, Michael Korvac, Red Guardian, Skurge the Executioner, Swordsman, Terrax the Tamer.
All but Captain America and Hawkeye died during the Grandmaster's tournament and the deceased were subsequently added to his Legion of the Unliving. The killed heroes inducted included Black Knight, Captain Marvel, Doctor Druid, Hank Pym, Iron Man, Mockingbird, She-Hulk, Silver Surfer, Thor and Wasp. Hawkeye eventually managed to defeat Grandmaster in a contest of his own making and those fallen Avengers and Silver Surfer were returned to life.
The next iteration of the team was assembled by Immortus who was holding the Scarlet Witch captive in hopes of making her his wife and Queen. The Avengers travelled to Limbo to free their team-mate from Immortus where they faced Immortus' own Legion of the Unliving which consisted of the former Black Knight, Grim Reaper, Iron Man 2020, Left-Winger and Right-Winger, Oort the Living Comet, Swordsman and Toro. The Avengers made short work of the Legion who were easily defeated.
Fear the Reaper
When the Grim Reaper sought to destroy the Avengers he formed a new Legion of the Unliving bringing back some dead enemies of the team to destroy them. They consisted of Amenhotep, Baron Zemo, a Black Knight, Count Nefaria, Inferno, Nebulon, Necrodamus, Red Guardian and Star Stalker.
Always an Avenger
During a festival celebrating the Avengers, the Grim Reaper again set his sights on the team again and led a new Legion of the Unliving to battle thm. This team consisted entirely of dead members of the Avengers including Captain Marvel, Doctor Druid, Hellcat, Mockingbird, Thunderstrike and Wonder Man. The team defeated the Avengers and even took control of Avengers Mansion until the Scarlet Witch managed to convince them to overcome Grim Reaper's control and remember their lives as heroes and members of the Avengers. Teaming up with the living Avengers, the dead Avengers helped the team defeat Grim Reaper.
New Kingdom of Vampires
A new Legion of the Unliving, made up solely of vampires, incited a vampire civil war to weed out the weaker ones, including Dracula. This got them the attention of the Avengers. Meanwhile, Dracula was protected by Russia's Winter Guard and eventually exiled to the Chernobyl Exclusion Zone. The Avengers would eventually think they defeated the Legion. However, the Legion would be revealed to be working with Dracula, to get him Chernobyl, where they can rebuild the vampire kingdom.