A three-issue sequel written and illustrated by Miller, "The Dark Knight Strikes Again", was published in 2001. A nine-issue third installment, ', co-written by Miller and Brian Azzarello, was published approximately bi-monthly starting in late 2015. In addition, a 64-page Prestige Format one-shot co-written by Miller and Azzarello, "Dark Knight Returns: The Last Crusade", which serves as a prequel to the original series, was released on June 15, 2016. Additionally, "Spawn/Batman" was released in 1994 as a companion to "The Dark Knight Returns", and, according to Miller, the unfinished series "All Star Batman & Robin, the Boy Wonder" can be considered a prequel, as can the four-issue story '.