How much of Batman's comic history can be fitted into a single timeline?

[Ubauba01]

Starting from the Golden Age, how many of the issues and story arcs can fit into a single timeline for Batman without condradicting each other?

Or altenatively, which stories can't fit?

[Restingvoice]

Well I can tell you right now the origins don't

[Ubauba01]

Well I can tell you right now the origins don't

I've read the Man who Laughs in which Batman first meets Joker. How many variations on that story are there, I wonder.

Or how about Year One?

[marhawkman]

Batman's stories have the same problem as Bruce Wayne's daily schedule which needs at lest 39 hours in each day. How many things happen all in one year?

[Restingvoice]

I've read the Man who Laughs in which Batman first meets Joker. How many variations on that story are there, I wonder.

Or how about Year One?

Man Who Laughs is set after Year One, but it's an adaptation of the original Golden Age story in Batman #1, and in Rebirth during Joker War it's adapted again. The broad stroke is the same, the first victim is always Henry Claridge and the climax is always poisoning the water reservoir, the difference is whether Dick Grayson, Alfred, or Gordon are involved, and how many other victims.

In opposition of Year One, we have Zero Year

[bat39]

Obviously there are some contradictions, and a lot of stories retelling the same events (Year One vs. Zero Year, for instance). But for the most part, Batman's entire comic-book history can fit into one coherent timeline...unlike, say, Superman or Wonder Woman.

Batman has never had a hard reboot. He's been soft-rebooted twice - after COIE, and with the New 52 - and a lot of the past continuity erased due to both of these has been restored.

If you want to see how Batman's history could fit together on one timeline, check out Morrison's run, specifically a two-parter called 'Last Rites'. Granted, this was published years before the New 52 reboot (though I'm sure with Rebirth a lot of it is back in canon again).

Apart from cosmetic stuff, the really big changes to Batman continuity have been:

1. Alfred being the Wayne butler since Bruce was a child (or in some cases before he was born), and being the one to raise him - elevating him to the status of a surrogate father and Bruce's most trusted ally and confidant.

2. Jason Todd's backstory changing from a redhead circus boy who's parents were killed by Killer Croc, to the current more iconic version, where he's a street kid who was caught stealing the Batmobile's tyres.

3. Cassandra Cain and Stephanie Brown were both rebooted into being recent entrants to the Bat-family, with their past histories as Batgirl and Robin/Batgirl respectively being wiped clean (I'm unaware if this has been reversed).

[mib86]

I think most of Batman story can fit quite well in a 13/15-year timeline, as Morrison tried to do during his run (Also it would be hard to fit in 4 Robin an 3 Batgirls).
Of course there are a lot of inconsistencies and some stories have more than one version, but you can easily explain this with time travel and the butterfly effect which in the DC universe are basically everyday events.

[Digifiend]

3. Cassandra Cain and Stephanie Brown were both rebooted into being recent entrants to the Bat-family, with their past histories as Batgirl and Robin/Batgirl respectively being wiped clean (I'm unaware if this has been reversed).

They found about about their past histories at the end of the Rebirth Detective Comics run by Tynion. During Joker War, in light of this knowledge, Cass reverted to her original costume. Steph added a bat emblem to hers but it still looks more like her Spoiler costume than her Batgirl one. Steph's time as Robin was confirmed to be back in continuity in the Robin 80th anniversary special, though that omitted Batgirl as an alias for her. I'd say everything up to around 2009 has been restored, but not necessarily everything that happened in the last two years before New 52.