The man known as Micky Moran died in the first issue of the British magazine the Warrior. The very same issue than re-birthed the 1950s Shazam rip-off, Marvelman, by newcomer Alan Moore. It was in this issue, that the reporter known as Micky Moran was taken hostage and with a sudden burst of memory, he shouted a word that hadn't been uttered for years. As Moran said "atomic" backwards, that man died as Marvelman returned forever.
It was this opening that so few today have experienced. In Britain, Marvelman had became Miracleman and had became a over seas exclusive. With it's social satire of the 1980s and the grim world around it, the book became a groundbreaking hit.
But how exactly? To even a religious comic book reader, he may still be unfamiliar. How exactly can he be famous if he isn't popular. Well, first let me say, I won't talk about the McFarlane v. Gaiman dispute or anything akin to that. I'm going to talk strictly about the book.
1. The Pitch:
When asked about Marvelman today, Alan Moore says that his overall idea of the book was to take the 1950s stereotype of the perfect, smiling, superhero family facade and adapt it to the 1980s. History shows that if there was ever a time in the 20th century that was polar opposite to the post-WWII optimistic 1950s, it was the 80s. Corruption, violence, drugs, and the Cold War were all the rage in this period. Yet, the comic book medium who had once taken upon itself to face issues like World War 2 was now avoiding these 80s issues. Alan Moore felt it was necessary to do this, and at the time, felt it would be revolutionary. It was also at this time that the now constant idea of realism and dark tones in comics appeared. Moore gave these heroes flaws and issues as well as a hunger for power as Moore felt that these traits would be prevalent in real life superheroes. Simply put, it was Alan Moore's pre-Watchmen Watchmen.
2. The Violence:
Comics in the 80s were avoiding the issues. The CBC was preventing excess violence and graphic content still and while Stan Lee fought against the CBC a few years before, Alan Moore and John Totleben took it a step forward. In a world where the only heroes were the Marvel family, Moore decided to apply realism to this too. Marvelman was taking out enemies by flying them into space, smashing heads into each other, flying completely through people and even simply pushing his index finger directly through their chests. It was utter gore. It was balls-out madness but it meant something. This violence wasn't pointless Bam-and-Wham stuff, because each part of the violence had meaning. It either symbolized the recognizable madness that was consuming the hero or it demonstrated the pain the characters were suffering. It was ballsy, and was borderline controversial. That was, until, issue 15 when Marvelman's fromer sidekick, the grown Kid MM, went insane and did this:

In an absolute fit of rage after the child alter ego of Kid MM was being raped by bullies, that Kid MM went on a massacre through Britain as our hero was off planet. Impaling bodies on Big Ben, hanging people nude in the streets, destroying buildings, ripping apart children, Kid MM was a super villain applied to the real world. Yet, not only did it represent the insanity of Kid MM but it was a satire of how quickly the morally corrupt and powerful politicians were destroying the world at the time. Even to the MM faithful, this move on Moore's part was shocking. It was condemned by the public and was ignored and forgotten. But Moore had one final brilliant act of violence in store. In order to take care of Kid MM,who had since reverted back to his child ego after an intense fight, our hero crushes the head of his former sidekick. Thus, causing MM to be unrivaled in power and was now viewed as a god.
3. The Dialogue
Within the conversations of the characters, you truly got a sense of the impact of events on the characters. If it were written as a book, it would be held up to par with many notable works, which few comics could boast at the time. In these conversations, the 1980s subject were brought into light. These topics were truly challenged and were faced head on.
4. The God Complex
In the series, Moran was revealed to never have been human to begin with but was alien in nature. Like Superman, he was a reporter with a family of heroes with similar powers. However, in Moore's run this changed. After the British Massacre, the Marvel family were revered as gods and were treated as such. This idea was continued in Gaiman's run as well and very much satirized the political power in the 80s and how they were revered and unrivaled by the public. It sent a message. Marvelman left us with issue 24 as Miracleman and his family were basking in their utopia as gods as Kid MM was resurfacing in the background. In all, the finale of Miracleman was cut short and left us thinking... this is probably how a superhero of such power would be seen today. And that changed alone changed the medium forever.
Like the late J.D Salinger's masterpieces, Marvelman took risks. It broke the mold and challenged what was considered a social norm in a time in which the public were ignorant to current issue. But it doesn't only represent the time period, MM could be applied to even today like Salingers masterpieces. Using violence, dialoge, and symbolism of the negatives of it's current time period, MarvelMan changed comics forever.