Written in 1980, The Untold Legend of the Batman, written by Wein and illustrated by Jim Aparo (still the best Batman artist of them all) retconned and welded together all of the various origin stories for Batman, Dick Grayson, Alfred, and the Joker that had been featured in comics in a pre-internet era where the general audience might not have anything other than a vague idea of how all of these characters came to be. This was the story that explained how Alfred was a former special forces soldier who was also a former actor who was also the son of the last butler for the Wayne family. It was the story that explained how the Waynes were murdered by Joe Chill, random mugger, but also mobster Lew Moxon, who was tabbed as the murderer in some early version of the story (Chill was working for Moxon, who put a hit on Thomas and wanted it to look like a random mugging). If you wanted to know how Batman learned how to fight crime, be a detective, and why he chose vigilante justice over being a police officer, this was the story that caught you up to date in the early 80s.
While certain elements of the Batman legend must always remain constant, however, the details will always need to be periodically updated in order to keep the character relevant to the times. So it was that The Untold Legend of the Batman's heroic attempt to make a workable pastiche of all of the Golden/Silver Age Batman origins full of old-timey mobsters gave way to Frank Miller's Year One origin featuring a very Hells Kitchen-y Gotham inspired by the crime wave of 70s/80s New York. Even Miller's seemingly untouchable take was eventually supplanted by Scott Snyder's Zero Year, which gave us a Batman dealing with 21st century threats likes superstorms, climate change, computer viruses, and terrorism.
While certain elements of the Batman legend must always remain constant, however, the details will always need to be periodically updated in order to keep the character relevant to the times. So it was that The Untold Legend of the Batman's heroic attempt to make a workable pastiche of all of the Golden/Silver Age Batman origins full of old-timey mobsters gave way to Frank Miller's Year One origin featuring a very Hells Kitchen-y Gotham inspired by the crime wave of 70s/80s New York. Even Miller's seemingly untouchable take was eventually supplanted by Scott Snyder's Zero Year, which gave us a Batman dealing with 21st century threats likes superstorms, climate change, computer viruses, and terrorism.