Batman has had so many popular stories told that cover the vast palette of villains and psychological aspects that make the character so continuously intriguing. Yet, above all of them, the most influential on the character the numerous times he's been adapted to the big screen is without a doubt the 13-issue American comic book limited series The Long Halloween (Which was published from 1996 to 1997. The series, which saw Batman face a character named Holiday who killed someone each month over a year (Along with tying into the origin story of Harvey Dent's transformation into Two-Face), found a way to include an extensive roster of the Caped Crusader's rogue gallery.
The series' run was a particular influence on Christopher Nolan's The Dark Knight trilogy, especially the acclaimed middle installment, The Dark Knight. In fact, Matt Reeves' upcoming film The Batman also has taken inspiration from it, along with it's follow-up series Dark Victory. And now, after being an inspiration for other people's works, the series will receive a direct animated film adaptation as part of Warner Bros. Animation's lineup of DC animated features for 202. This was revealed this weekend at the DC FanDome event during the panel for their newest title Superman: Man of Tomorrow. That film was released digitally this past weekend.
The adaptation will be released in two-parts (Similar to the studios' adaptation of Frank Miller's The Dark Knight Returns) with both parts released in the latter part of 2021 (One in the Summer, on the Fall). It will follow several other adaptations that the studio is working on for the DC Animated Universe in 2021 including Batman: Soul of the Dragon and Justice Society: World War II, the latter will follow the Justice Society of America, the first-ever superhero team that preceded the Justice League. Stay tuned!