Nine of the most famous comics characters originated from the Golden Age Batman Universe and, the only exception being the Riddler, eight characters first appeared between 1939 and 1943 (in only five years!).
1939: Batman, Gordon, Doctor Death, Monk
1940: Robin, Joker, Catwoman, Hugo Strange, Clayface
1941: Penguin, Scarecrow
1943: Alfred, Cavalier, Tweedledum and Tweedledee, Crime Doctor
1947: Penny Plunderer
1948: Riddler, Mad Hatter
1951: Red Hood, Killer Moth
I find it fascinating.
What do you think? Any comment on this topic is welcome.
impressive list of villains, with likely the best staying power
of any Rogue's Gallery.