Happy Birthday, Superman - Or, as the new Man of Steel trailer would have it, "Su[insert distracting noise]." Today marks the 75th anniversary of the Last Son of Krypton, who has been fighting crime and saving his adopted world simply because that's the way he was raised. (Good work on that one, Ma and Pa Kent). But while Clark Kent's alter-ego has been a constant presence in comic books, movies and on television for the last seven and a half decades, he hasn't been constant in terms of characterization. Throughout his existence, Superman has changed to match the times, for better and worse. Here's a quick guide to the many faces of the Man of Steel.

Man of The People: When Superman was first seen in Action Comics #1 in 1938, he was as his creators Joe Shuster and Jerry Siegel imagined him: An uncomplicated hero who stood up for the little man against forces of corruption and tyranny in a country emerging from the depression. The original Superman was a man of action above all, seeing no problem with fighting the authorities as well as the criminals if he believed justice wasn't being served. He had no problem with killing, either, offing villains by destroying their plane in mid-flight or threatening heavies with having their "brains dashed out" on nearby walls if they didn't comply. Such youthful intensity wouldn't last long, however, especially as the character's popularity started to rise up, up and away.

Man of The Free: When America went to war, it only made sense that Superman would accompany it. What worse injustice existed in the world than the march of facism, after all, and who better to stand up against it? Unfortunately, Superman's wartime engagements were mostly limited to patriotic covers on comic books as he exhorted readers to support the war effort, and he occasionally indulged in genuinely appalling racism while he was at it ("Superman says: YOU can slap a Jap with War Bonds and Stamps!" declared the cover of Action #58). As World War II changed society, Superman changed with it, becoming more of a dependable authority figure than before.

Man of The Family: Post-War, America tried to get back to normal with a new cultural focus on domesticity; the phrase "nuclear family" entered everyday usage, and the Man of Steel found himself a family of his own to match. Alongside work-wife (although, of course, she longed for more) Lois Lane, Superman gained a cousin (Supergirl, who crash-landed on Earth in 1958), a pet (Krypto the Super-Dog, whose first howls were heard in 1955) and an entire extended family of fellow Kryptonians in the miniature Bottle City of Kandor (1958 again) — all of which distracted from the fact that, after the Nazis, regular bad guys just didn't seem as threatening anymore.

Man of The Moment: As the 1950s and early '60s went on, Superman had more to do than wrestle with family duties and run of the mill criminals, of course. With superheroes mostly out of vogue, the Man of Tomorrow's adventures occasionally wandered into the era's more popular genre, the monster movie, thanks to whatever deus ex monstera methods happened to be available at the time. "Red Kryptonite" would transform the hero into alternate versions of himself — He has the head of a lion! He looks like an insect! His morality has become reversed! and so on — while magic, science or any combination of the two would regularly do the same to his friends and foes. As the country unconsciously prepared for cultural transformations via the rise of the teenager, rock and roll and the Summer of Love, Superman paved the way by demonstrating how flexible personality and sense of self could be.

Man Out of Time: Once America had dealt with real-life hippies and glam rock stars, Superman — at this point, 40 years old and still a reporter for a mild-mannered metropolitan newspaper with suit, tie and hat to match — seemed more than a little out of date… And perhaps a little too powerful, too, considering he could fly in space and travel through time entirely unaided by this point. The only solution: A soft reboot, which saw Superman significantly de-powered and Clark Kent given a new job as a television news anchorman — complete with new comedy co-workers, updated wardrobe and newly laid-back attitude towards life. It didn't last, with 1978's Superman the Movie cementing the Daily Planet and nervous, uptight Clark in mainstream audience's minds once again.

Man of Means: In the mid-1980s, DC Comics went for broke. Thanks to the massively-successful Crisis on Infinite Earths series that allowed the publisher to relaunch most of its premiere characters, Superman got a do-over courtesy of John Byrne, one of the comic industry's most-popular creators at the time. Massive swaths of the character's mythos — including his entire teenage career as Superboy — were washed away, with Clark Kent going from clumsy loser to Pulitzer Prize-winning journalist and novelist who romances a similarly-successful Lois Lane. Meanwhile, Lex Luthor fumes and schemes in the background, no longer a mad scientist but a hyper-wealthy corporate shark. It was the '80s: Greed was good for everyone, it seemed.

Man of The Past: Such success couldn't last, of course. After the yuppie-centric 1980s reinvention, there came 1992's massively-successful "Death of Superman" storyline, in which Superman — by this point, engaged to Lois Lane, who knew about his double identity — sacrificed himself to save Metropolis from a monster with the unsubtle name "Doomsday." If the storyline seemed shoddy and half-baked, that's because it was. It was a long-running joke amongst Superman writers that became a reality when they suddenly needed to delay Superman's wedding to Lois to accommodate the schedule of the concurrent Lois and Clark TV series. That didn't seem to impact sales, with the storyline breaking sales records and making the character more popular than he'd been in years, if not decades. The best Superman, it seemed, was a dead Superman.

Multiple Men of Steel: Of course, Superman wouldn't stay dead for too long. He was back in Action (and his three other regular comics) within a year, in fact — complete with a mullet, because temporary death turns you into Billy Ray Cyrus — but not before four new characters had been created to try and take his place. Of those four, one turned out to be evil, one merely morally compromised (and not even a person, as such), but the remaining two ended up becoming important additions to the extended Superman family. Superboy was a teenage clone of the Man of Steel whose powers were similar but whose attitude more in tune with the "extreme" 1990s, and Steel was John Henry Irons, a regular guy (albeit one who happened to be a genius inventor) who tried to keep Superman's memory alive with an Iron Man-esque suit of armor. Neither could replace Superman permanently, but both expanded the Superman demographic just that little bit…

Man of Emotion: Having died, been reborn and eventually managed to marry Lois, Superman entered the 21st century a new man, one who was, for the first time, was in touch with his feelings. So in touch was he, in fact, that watching Superman clench his fist in barely-restrained angst or cry one single tear quickly became the benchmark with which fans could identify the seriousness of a particular storyline. (If both things happened, then you knew it was a big deal). The problem with this emotional Superman, however, was that he could be too busy feeling to actually do things. As Batman cruelly told him in the first issue of 2006's Infinite Crisis, "the last time you really inspired anyone was when you were dead." As you might expect, writers and artists tried a course correction to fix this, but before too long, the character was walking across America, trying to reconnect with the common man. Something drastic needed to be done.

Man Reborn: For the second time in its history, DC Comics wiped everything clean and started anew in 2011 following its Flashpoint series. As part of "The New 52," there was once again a new, younger Superman, one more closely modeled after Siegel and Shuster's original social crusader. (As he said during the first issue of the second volume of Action Comics, "You know the deal, Metropolis. Treat people right or expect a visit from me"). How quickly this new Superman will come to not only conform to, but uphold and ultimately represent, the status quo remains to be seen - He's certainly already on his way in such series as Superman and Justice League — but if the character retains a little bit more of an edge as a result of this rebirth, that might not be too much of a bad thing.

Man of Steel: So what makes Superman Superman, throughout all of these reinventions and restylings? Is it the costume and the powers? Well, in part, but even those change. Those red trunks disappeared with the 2011 reboot, for example, and his powers have constantly been in flux throughout the decades. His personality, too, has been through revisions both subtle and major, so it can't be that, either. Instead, what makes Superman so recognizable is the underlying attitude of the character: At the heart of the concept, he's the guy who believes in the good of people, and who'll never give up fighting anything and everything that threatens that optimism and utopian outlook. Superman wants the world to be a better place, and fights for that on a regular basis so that other people don't have to. What makes Superman Superman is hope; something that the latest Man of Steel trailer picks up on. Unlike other superheroes, he doesn't want to scare you, or gain your sympathy for his hard luck life. He wants you to look up. Up in the sky.