Reign of the Empire covers the gap between Revenge of the Sith and A New Hope. It is a long stretch of stable tyranny, and it produces a very particular kind of novel: procedural, cold, and interested in how ordinary competence becomes complicity.
The shape of the era
Nineteen years is a long time to fill, and the publishing programme has filled it mostly with institutional stories — officers, bureaucrats, surveyors, smugglers, mid-level administrators discovering what they are actually part of. The rebellion in this era is not yet an alliance. It is a scatter of cells that mostly do not know about one another, and the drama of the period is the slow, dangerous work of introducing them.
The Jedi are gone
Not entirely — but functionally. A handful survive by hiding so thoroughly that they stop being Jedi in any practical sense. The Empire runs Inquisitors to hunt the remainder, and the most striking thing about the era's Force material is how little of it there is: for two decades the galaxy simply forgets, and by A New Hope a starfighter pilot can call the Force a hokey religion without being contradicted.
Thrawn
Timothy Zahn's Thrawn (2017) is the obvious door into the era. It brings the character across from Legends into canon and rebuilds him as an outsider climbing an explicitly xenophobic hierarchy, which turns out to be a much better engine for a novel than tactical genius alone. Every promotion is a plot point; every victory has a political cost. See also the dossier.
Canon and Legends
Both continuities are strong here and they diverge completely. Legends built this period around The Force Unleashed, the X-wing and Han Solo prequel novels and a much earlier, much more organised Rebellion. Canon rebuilt it around Rebels (2014–2018), Rogue One (2016) and Andor (2022–2025), and pushed the Alliance's formal founding all the way to 2 BBY — which makes the Rebellion of the original film about two years old, and much more fragile than it looks.
Andor in particular has changed how this era reads. It treats occupation as an administrative problem rather than a moral one, and its Empire is frightening because it is competent and bored rather than because it is evil.
Everything here converges on Scarif, and from Scarif into Age of Rebellion.