This is book 4 in the Safehold series. The framing story is that the remnants of humanity are hiding out on a far planet from a nasty alien race and have to abandon technology. Unfortunately the handlers had a difference of opinion on how to do this, and fought. The winners imposed a religious theocracy over the planet. Now a thousand years later, one ‘man’ has to work underground to break the hold of the theocracy to let man develop again.
In effect, though, this book is virtually an alternate history of the reformation era on earth. The new technology that is introduced are cannon based galleons and naval cannon instead of the almost traditional ‘advanced gunpowder weapons’ in books like Lord Kalvan of Otherwhen.
It reads like a history as well, as the huge number of characters keeps any one person from shining as a character. Even ‘Merlin’ the world changer, is reduced to watching and waiting on developments and trying to build the resources of his alliance opposing the Theocracy.
Now, as you can tell, I like reading history, so this suits me fine. If you want a more character driven story, then this series won’t be for you.