The Golden Age era laid the foundation for the Batman universe. Bob Kane and Bill Finger created the character in May 1939 in Detective Comics #27. The Joker appeared as early as Batman #1 in 1940. The gallery of classic villains (Catwoman, Penguin, Riddler, Two-Face) took shape. The tone was still close to detective pulp fiction, without the psychological darkness of later eras.

Silver Age = science fiction, time travel, Batman in space, whimsical gadgets. An era long scorned by modern fans but one that introduced the DC Multiverse (parallel Earths) and created the pop tone that would inspire the 1966 Adam West series and then Joel Schumacher in the 90s.

An era of serious storytelling. Denny O'Neil and Neal Adams brought Batman back into the night. In 1976, Detective Comics #457 'There Is No Hope in Crime Alley' canonized the name 'Crime Alley' and introduced Bruce Wayne's annual ritual. The Bronze Age paved the way for the Modern Age revolution that would arrive in 1985.

The Modern Age begins in 1985 with Crisis on Infinite Earths, which reset all DC continuity. This clean slate paved the way for the masterpieces that would define Batman for the next forty years. Frank Miller, Alan Moore, Grant Morrison, Jeph Loeb signed their major works. This era probably contains 80% of the most important Batman comics ever written.

In 2011, Flashpoint erased DC continuity and launched The New 52. Scott Snyder became Batman's main writer. He started in 2010 with The Black Mirror and then launched the Court of Owls saga, which reinvented Gotham's ancient history. An era dominated by Snyder and his artist Greg Capullo. Introduced Damian Wayne as the new canonical Robin.

In 2016, DC Rebirth partially restored the pre-Flashpoint continuity. Tom King became the main writer for Batman with psychological arcs (Bruce-Selina romance leading to an aborted marriage). James Tynion IV wrote War of Jokes and Riddles. Scott Snyder launched Dark Nights: Metal which introduced the Batman Who Laughs.

In 2018, DC launched Black Label, an imprint dedicated to adult, out-of-continuity works by a single author. Sean Murphy led the way with Batman: White Knight in late 2017. The label would then produce Damned, Three Jokers, Batman/Catwoman. It demonstrates that Batman can be radically re-imagined by unique authors with editorial carte blanche.