Marvel Cinematic Universe, they were often the team that stood in the center of most Marvel non-mutant event series. In their own comics, they also featured several events that altered the course of comic book history.
These major events go back a long way, as it was in the 1970s that the Avengers introduced the Kree-Skrull War in the pages of its comics, a war that stretched out into the Cosmic Marvel Universe. Add in events that shook up every hero in Marvel and even a couple that brought the mutants into the battle, and the Avengers' top events remain some of the most important moments in Marvel history.
Avengers Disassembled
One of the most devastating events in Avengers history came in 2004 with the series Avengers Disassembled. Vision and Jack of Hearts died at the start and by the end, while Scott Lang's Ant-Man and Hawkeye died in what appeared to be a battle with the Kree. However, the shocker came at the end.
The Kree had never attacked and this was all conjured by Scarlet Witch after she learned of her children's existence. She also killed Agatha Harkness. What keeps this from being more important is that every death was retconned later. The event is still important as it led to the crossover series House of M.
The Kree-Skrull War
The Kree and Skrull Empires have been at war for over a million years. At one point, the Kree sent a spy to Earth in Captain Mar-Vell to work as a sleeper agent. However, Mar-Vell chose to remain loyal to Earth and this led to the Kree-Skrull War event series in Avengers #89-97.
This took the Avengers to a cosmic level that had never really experienced when they ended up in the middle of the war between the two empires while having to fight both to save the planet. This was also the first notable Avengers event series and served as a basis for the story in the MCU movie Captain Marvel.
Ultron Unlimited
Ultron Unlimited was the best Avengers event series featuring one of their most dangerous villains, Ultron. This took place in Avengers Vol. 3 #19-22 and basically rewrote what the android villain is all about. This all started when Ultron destroyed an entire country.
Ultron then turned its dead citizens into cyborg warriors in what ended up as the basis of the MCU movie Avengers: Age of Ultron. This is the series where the truth is revealed that Ultron's brainwaves were based on the actual persona of his creator Hank Pym, changing everything readers knew about the two enemies.
Avengers Vs. X-Men
In 2012, Brian Michael Bendis, Jason Aaron, and Frank Cho started one of the biggest crossover event series in Avengers history with Avengers vs. X-Men. This event started when the Phoenix Force headed back to Earth and the Avengers decided to lock away Hope Summers for her's and the Earth's protection.
The X-Men wouldn't hear anything about this and went to war with the Avengers to protect Hope from them. The Phoenix Force arrived and possessed several X-Men instead, making the war deadlier than ever. This series was very important and played a big role in the mutant's relationship to other heroes while making Cyclops a mutant martyr in the end.
Civil War
Civil War was a company-wide Avengers crossover in the 1990s, but its foundation rested in the pages of The Avengers. The book had two of the longest-tenured and respected Avengers take different sides on a controversial law - the Superhero Registration Act. With Iron Man on one side and Captain America on the other, the world's heroes turned against each other.
This changed everything for a long time in comics. In the end, Captain America died after surrendering and the heroes didn't trust each other for a very long time. The comics remain polarizing for fans, but it did end up as a popular movie in Captain America: Civil War.
The Kang Dynasty
One of the Avengers' most dangerous villains - and the next big bad in the MCU - is Kang the Conqueror. The best Kang event series in Avengers comics was Kang Dynasty in Avengers Vol. 3 #41-55. Kang showed up on Earth and became the first person to successfully take over the world.
Kang gathered several villainous forces on Earth to aid him, as he promised they could rule their own lands, using Earth's own citizens to fight for him. The series remains memorable, as Kang proved he was more powerful than all Earth's heroes and it was only through betrayal from one of his own that he could ever fall.
The New Avengers: Breakout
After many years of the Avengers working as government agents and featuring the most powerful superheroes in the world, it was time for a change. Avengers Disassembled saw the team break up and go their own separate ways, but there was still a need for an Avengers team. This was the New Avengers.
"Breakout" was the first event in the debut New Avengers series. This book breathed new life into the team, with only Captain America remaining onboard, and the rest of the team as street-level heroes like Spider-Man, Luke Cage, Daredevil, and Spider-Woman.
Avengers Forever
Avengers Forever was a 1998 event series that could have easily failed. It featured Rick Jones, the man who brought the team together originally, in a time travel story where he works with Avengers from different points in their history to work together.
This remains one of the best Avengers events ever written as it actually drops into comic book stories from the previous 30 years, playing out like a giant love letter to the team's history. This was a 12-issue series with the Avengers battling Immortus throughout the timeline.
Avengers: Under Siege
It is rare for regular supervillains to beat the Avengers, but this happened in Avengers: Under Siege, a 1980s Avengers event comic series that remains on most people's list of the best stories in the team's history. The villains here were the Masters of Evil, led by Baron Zemo and lasted from Avengers #270-277.
The story was shocking as the villains attacked the heroes at Avengers Mansion with no warning and defeated and captured everyone but Wasp, even putting Hercules into a coma. The villains' beatdown of Jarvis was especially disturbing. This series ranks high on most fans' lists because it showed the Avengers at their lowest, forced to give it their all to overcome the odds and defend their home.
The Korvac Saga
The best Avengers event series of all time was The Korvac Saga. This saw the team battle an all-powerful cosmic force named Michael Korvac. This man wanted nothing more than to create a utopian world on Earth for all to live in peace and happiness.
However, this was at the expense of most free will. This series remains memorable as the one fight the Avengers couldn't win, as Korvac ended up killing the entire team and they couldn't stop him. It was Korvac himself who finally realized what he had become and brought the Avengers back before leaving voluntarily, showing even Earth's Mightiest Heroes couldn't beat all threats.