The 'original' timeline-altering event that cause the shift from GA to SA...

[bat39]

In Doomsday Clock (which admittedly I've yet to actually read), when Manhattan is observing the various continuity shifts that occur around Superman, he talks about the various forces that have triggered continuity changes - Krona, Anti-Monitor, Extant, and himself.

We know that COIE caused the shift from Silver Age/Bronze Age to Post COIE. That Manhattan himself caused the shift to the New 52. The return of Wally West and the re-merging of the two Supermen caused the latest ongoing shift.

But my question is - what caused the original continuity shift that Manhattan observed? The one which caused the transition from Golden Age to Silver Age. Or in other words, the one which caused Superman to go from showing up in 1938 to showing up in 1956.

I know the traditional explanation has been that there was no 'continuity shift' but the comics simply started following another earth at that point. But DDC now establishes the fact that on the 'mainstream' earth (or Prime Earth or whatever you want to call it), Superman did once debut in 1938, and the transition to the Silver Age version was yet another timeline shift/reboot.

So what caused this timeline shift?

Could it be Krona's original experiment that created the Multiverse? Could it be that in reaching back to observe creation, he inadvertantly not only triggered the birth of the Multiverse, but wiped out the JSA from earth's history and moved forward Superman's origin (with something akin to the 'original timeline' continuing to exist on the parallel earth we call 'Earth Two')?

Or was it something else?

What's interesting about this continuity shift is that, unlike other shifts, its had a permanent impact on DC continuity and on the DC brand at large! Changes from COIE, IC and now the New 52 have been undone, but the original shift from Golden Age to Silver Age has persisted throughout every subsequent incarnation of the DCU...in the comics and across media.

Superman, Batman and Wonder Woman are widely considered to be contemporaries (if not founders) of the Justice League. The 'iconic' GL and Flash are Hal and Barry, not Alan and Jay, and the GL and Flash mythologies have largely been based on the Silver Age interpretations. The Silver Age remains the 'base template' of the DCU, and has since the late 50's/early 60's. Silver Age characters and concepts have thrived, while Golden Age ones, by and large, have been relegated to the sidelines.

Even the new DC timeline, which otherwise represents continuity as it originally happened, is slaved to this original continuity shift - ensuring that Superman and Batman are contemporaries of the JLA, not JSA (Wonder Woman is the one exception, and in her case, it might have more to do with movie synergy that an attempt to honor the Golden Age continuity).

[Electricmastro]

I think that it had largely to do with More Fun Comics #101 (January, 1945), the issue where Superboy debuts, as I think the Superman that you see in Justice League of America #1 (November, 1960) is not the Superman from Action Comics #1, but was originally the Superboy from More Fun Comics #101.

[Tzigone]

I think that it had largely to do with More Fun Comics #101 (January, 1945), the issue where Superboy debuts, as I think the Superman that you see in Justice League of America #1 (November, 1960) is not the Superman from Action Comics #1, but was originally the Superboy from More Fun Comics #101.

When did Superman start acknowledging Superboy? From what I recall reading for a long while they were at least somewhat treated as different continuities.

And did every title switch at the same time?

[Jim Kelly]

The references to Superman as Superboy were sporadic, but the first one I can find is in SUPERMAN 46 (May-June 1947), "That Old Class of Superboy's" by Jerry Siegel, John Sikela and George Roussos. Contradicting that are stories like "The Origin of Superman," by Bill Finger, Wayne Boring and Stan Kaye, in SUPERMAN 53 (July-August 1948), where, even though they show Clark as a boy, they never show him as Superboy.

I'd probably locate the "event" that caused the split in continuity to be later around 1958, when a lot of the stuff that we call "Silver Age" starts to get nailed down in the continuity. In terms of Superman/Superboy there's a few important things that happen: Superboy meeting the Legion for the first time; Superman's encounter with Brainiac (and the bottle city of Kandor); Supergirl arriving on Earth (although a Supergirl was earlier glimpsed when Jimmy produced her by rubbing a magic totem).

It seems like DC has abandoned Grant Morrison's great project of mapping out alternate universes in the multiverses and has instead decided on multiple continuities in the same universe.

[bat39]

The references to Superman as Superboy were sporadic, but the first one I can find is in SUPERMAN 46 (May-June 1947), "That Old Class of Superboy's" by Jerry Siegel, John Sikela and George Roussos. Contradicting that are stories like "The Origin of Superman," by Bill Finger, Wayne Boring and Stan Kaye, in SUPERMAN 53 (July-August 1948), where, even though they show Clark as a boy, they never show him as Superboy.

I'd probably locate the "event" that caused the split in continuity to be later around 1958, when a lot of the stuff that we call "Silver Age" starts to get nailed down in the continuity. In terms of Superman/Superboy there's a few important things that happen: Superboy meeting the Legion for the first time; Superman's encounter with Brainiac (and the bottle city of Kandor); Supergirl arriving on Earth (although a Supergirl was earlier glimpsed when Jimmy produced her by rubbing a magic totem).

It seems like DC has abandoned Grant Morrison's great project of mapping out alternate universes in the multiverses and has instead decided on multiple continuities in the same universe.

I don't think the two are mutually exclusive, really. Its established in the DCU that there are parallel universes, but also alternate timelines/realities that shift in the same universe.

Its long been established that all the various incarnations of Superman from the Silver Age onwards were basically the same guy changed by timeline-altering events. All DDC did is establish that the Golden Age Superman too was the same guy who was altered into the Silver Age Superman. The fact that a version of the Golden Age Superman came to exist in a parallel universe called Earth Two doesn't contradict that.

But I'm really curious to know what is the in-universe reason for the reboot that forever separated Superman from the era of the JSA.

[CaptCleghorn]

I don't think the two are mutually exclusive, really. Its established in the DCU that there are parallel universes, but also alternate timelines/realities that shift in the same universe.

Its long been established that all the various incarnations of Superman from the Silver Age onwards were basically the same guy changed by timeline-altering events. All DDC did is establish that the Golden Age Superman too was the same guy who was altered into the Silver Age Superman. The fact that a version of the Golden Age Superman came to exist in a parallel universe called Earth Two doesn't contradict that.

But I'm really curious to know what is the in-universe reason for the reboot that forever separated Superman from the era of the JSA.

Crisis on Infinite earths seperated Superman (and Batman) from the JSA.

It's not a complicated setup. Jay Garrick and Alan Scott were on Earth Two; Barry Allen and Hal Jordan were on Earth-One. Until COIE, the was no even splitting the two. Many stories took place on Earth-One and many others took place on Earth-Two. Except for Superman, Batman, Wonder Woman, Aquaman, and Green Arrow the switching point between Earths One and Two are blatantly obvious.

Now where the Super Friends and Green Arrow have their switching points is unknown. In fact, it may even be possible there is no set point but stories eventually going from one world to the other. Going through back issues and trying to identify stories as Earth-One or Earth-Two is far too lengthy and complicated a process for me to care about.

[Tzigone]

I'd probably locate the "event" that caused the split in continuity to be later around 1958, when a lot of the stuff that we call "Silver Age" starts to get nailed down in the continuity. In terms of Superman/Superboy there's a few important things that happen: Superboy meeting the Legion for the first time; Superman's encounter with Brainiac (and the bottle city of Kandor); Supergirl arriving on Earth (although a Supergirl was earlier glimpsed when Jimmy produced her by rubbing a magic totem).

Sounds good.

I know Batman's is often set in 1954 because of Catwoman.

Not at all sure about Wonder Woman.

And, of course we all know Barry premiered in 1956, and is definitely silver age.

But I'm really curious to know what is the in-universe reason for the reboot that forever separated Superman from the era of the JSA.

An in-universe reason would be really great. I mean, I prefer the "separate universes" method, but if they are same universe, knowing what and why the universe changed is definitely a plus. Maybe the event is worthy of it's own mini, even.

[Jim Kelly]

My personal favourite is the bottle city of Kandor--as it's a kind of literal and metaphorical genie in a bottle that when released transforms the reality around it. But I'd also put money on the Legion, because by going back in time they could have changed the timeline itself--and since they go back to when Superman was a boy, they affect the time before the other heroes appeared on the scene (like Batman and Flash). It's a temporal paradox--they go back in time to find the mythical Superboy, but in turn create the very thing they went to find.

[Electricmastro]

The references to Superman as Superboy were sporadic, but the first one I can find is in SUPERMAN 46 (May-June 1947), "That Old Class of Superboy's" by Jerry Siegel, John Sikela and George Roussos. Contradicting that are stories like "The Origin of Superman," by Bill Finger, Wayne Boring and Stan Kaye, in SUPERMAN 53 (July-August 1948), where, even though they show Clark as a boy, they never show him as Superboy.

I'd probably locate the "event" that caused the split in continuity to be later around 1958, when a lot of the stuff that we call "Silver Age" starts to get nailed down in the continuity. In terms of Superman/Superboy there's a few important things that happen: Superboy meeting the Legion for the first time; Superman's encounter with Brainiac (and the bottle city of Kandor); Supergirl arriving on Earth (although a Supergirl was earlier glimpsed when Jimmy produced her by rubbing a magic totem).

It seems like DC has abandoned Grant Morrison's great project of mapping out alternate universes in the multiverses and has instead decided on multiple continuities in the same universe.

There's also the matter of Superman and Batman being described as never having met before in Superman #76 (May, 1952),



even though Superman and Batman were previously seen meeting each other in All-Star Comics #36 (August, 1947).

[DrNewGod]

I like the Legion answer. Of course a fun one-off would replay some of the key scenes of Doctor Manhattan trying to figure it out, and concealed behind him, Mister Mxyzptlk snickering at the chaos resulting from the trick he's played on Doc.