The Bad Batch coincides with Order 66 in the year 19 BBY. Episode 1 would be happening at the same time as Anakin's betrayal of the Jedi Order, with most of the Jedi across the galaxy killed by their brainwashed clone troopers. It explores how the Empire turns from the highly-skilled but very costly clone troopers to much cheaper conscripted storm troopers, particularly under Tarkin, who has long been against the use of clones.