So what happened between then and the start of Birds of Prey that’s led to him vacating Gotham City?
When we left off with Batman at the end of Justice League, he seemed to be in a much better place than usual.
Either way, with Batman gone, that leaves it up to Birds of Prey’s eponymous team to fill the void and deal with whatever criminal elements present themselves.
Oh, and of course he was continuing to strike terror into the hearts of criminals as a creature of the night.