Earth-Forty is the official name of the second oldest official alternate reality of DC comics.
See the DC Database entry on Earth-Forty for more details.
Earth-Forty is an alternate universe, first described in Crisis on Infinite Earths: The Compendium (Nov., 2005)
Several Silver Age stories/comics were retconned in The Compendium to Earth-Forty. Theses stories include:
- Adventure Comics Vol 1 120
- Batman Vol 1 32, 131, 135, 145, 159, 163
- Batman: The Dailies 1–3
- Batman: The Sunday Classics
- The Legend of Wonder Woman 1–4
- Thrill Comics #1 (ashcan)
- Superman Vol 1 46
- Wonder Woman Vol 1 50, 156, 159, 165, 168
Bruce Wayne retired by the mid 1960's to make way for a new Batman and Robin Team. During this time he married Batwoman (Katherine Kane) and eventually retired passing the mantel of the Batman to his son Bruce Wayne, Jr.
- Crisis on Infinite Earths: The Compendium lists entire issues rather than specific stories, leaving the question if any non contradictory stories in those issues occurred on Earth-One, Earth-Forty, or both.
- The Compendium lists Thrill Comics, #1 (1940) as happening on Earth-Forty but doesn't count it as a first appearance (possibly because it was an ashcan comic)
- The Compendium also doesn't count the 1943 Batman newspaper strip as a first appearance of Earth-Forty either (possibly because it wasn't an actual comic book).
- The Crisis on Infinite Earths: The Compendium stated this was "revealed as a distinct parallel Earth in The Kingdom, #2" making this reality part of hypertime.
- Queen Hippolyta is depicted as a blond in The Legend of Wonder Woman, #1–4 rather than having brown hair as on Earth-Two.
- The Essential Wonder Woman Encyclopedia (2010) doesn't list Earth-Forty and assigns the "Golden Age" Wonder Woman stories to Earth-One resulting in those stories happening with variation on all three Earths.
- If one counts Thrill Comics, #1 (1940) as Earth-Forty's true first appearance and Convergence #0's implication that Earth-Two didn't appear until The Flash, #123 then it is one of the three oldest alternate realities officially identified (the other two are Earth-Two-A and Earth-Quality). In any case Earth-Forty is the oldest official hypertime reality.