(Warning - the following contains a whole lot of images of old-timey Batman killing people in various (often ridiculous) ways...)
One of the truly great things about comic books is that - due to the variety that exists within their ranks - there really is something for everybody. Want to read about teenagers in small-town America? There's Archie. Want light-hearted superheroic fare? Try Brian Michael Bendis' All-New X-Men, or Brenden Fletcher and Cameron Stewart's Batgirl (or pretty much anything from before 1980).
If you want dark, gritty, misery-soaked comic book adventure, though, there's a pretty good chance that most fans would send you in one very particular direction: Batman. After all, since the early 1980s, Batman has been as consistent a provider of 'grown-up,' downbeat noir as anyone else around.
The slightly odd thing about that, though?
Despite Being the Gritty Superhero, Batman Doesn't Kill
After all, as he never tires of telling everyone around him, he has a pretty cut-and-dried rule prohibiting both the use of guns, and the killing of anyone (even, as a rule, The Joker).
Now, sure, he breaks that stony commandment more than you'd think, but as a general rule (and excluding very particular, world-saving situations), Batman doesn't kill.
Except, of course:
Back in the 1940s, Batman REALLY Liked Killing People
As in, REALLY liked it.
Whether it was...
Punching a Dude into a Vat of Acid...
And then quipping cruelly, no less...
...Shooting Up a Truck with His Batplane...
Crucially, by 'this time,' he means pretty much every issue.
...Or Hanging a Guy from That Same Batplane
...it's probably safe to say that Batman was actually pretty on-board with fatal vigilante justice.
The Most Intriguing Part of All That, Though?
Remember how I said that Batman really liked killing people in the 1940s?
Well, that's actually not quite true. Instead, Batman was completely cool with brutally murdering people from his original appearance back in May 1939, all the way through to...late 1940.
So...for a little over a year.
At which point Batman very much adopted his famous 'no killing' rule in earnest, reminding Robin in December 1940's Batman #4 that "we never kill with weapons of any kind."
Even when fighting pirates, it seems.
So, What Changed?
Well, as Chris Sims of Comics Alliance has argued:
"As crazy as it might sound, the Batman who killed in those early stories wasn’t really Batman — or at least, not Batman as he’d become, and certainly not Batman as we think of him today."
Instead, he was a rough approximation of the character so widely beloved today - one who, for the first six months of his existence, didn't even have a back-story to speak of. It wasn't until Detective Comics #33 that Batman's original creators finally devised and published the death of Bruce Wayne's parents, and began the gradual process of transforming a fairly generic costumed crime-fighter into the true superhero Batman was to become.
So, all of that murdering? Sure, that was technically Batman, but only in the way that a whole lot of TV pilots have a different actor playing your favorite lead, or the first Iron Man movie features Terrence Howard as Rhodey. His creators hadn't worked out all the kinks yet - which, seeing as superhero comics were about a year old at the time, perhaps isn't overly surprising.
Which is how this:
Quickly became this:
And...then the '80s happened, and things got kind of murder-y again for a while there...
But, y'know what? That's a whole other story...