Or, I should say, pre-story: Humans have spread to the stars. A human ship finds an alien world with evidence of advanced life, but that life had been destroyed. Most believe the advanced intelligent life was destroyed by another intelligent race (Gbaba).
Gbaba finds one of human’s far-flung colonies. Gbaba destroy colony. War erupts. Humans were about even technology wise with Gbaba, even though the Gbaba had been around for 1000s, if not millions of years longer than humans. But the Gbaba are not flexibable, are not innovative. They have a stagnant culture. The Gbaba civilization is much larger than human, and therefore can overwhelm mankind.
Seeing the end of Man, “Mission Control” sends a colony fleet away from Earth using sneaky techniques to get away from observation (all other colony fleets tracked and destroyed - one got away, but scout ships eventually found that colony and destroyed it - believed technology signals emitting from colony lured the Gbaba to the colony).
Operation Ark sent out - 47 ships visible, 47 ships hidden from view. 47 ships then break away. Establish colony. Belief that technology will lead Gbaba to colony, a system is set up to deny use of any and all advancement of technology.
Adult colonists have minds altered with implanted false memories - believe they “awoke” fully formed as adults on the planet. “God” and his “angels” (the crew of the ships that deposited the colonists on the colony) “created” the adults, placed them on the planet, and the humans (Adam’s and Eve’s) told to reproduce like rabbits (not those exact words).
Story kicks off 890 years later when "robot/android" awakened. Has the memories and personality of a female Lt. Commander. This robot/android has to try to get the world ready for the coming of the Gbaba. To do that she needs to advance the tech base, and change the attitude towards the World Church.
Most of the book involves the robot with the female personality, attempting to change the world while assuming the role of a man named Merlin. The tech base is around 15th-18th century Earth (depending on specific technology). The World Church is suspicious of Charis Island (kingdom) and eventually leads a war against it. Naval battle ensues.
Review: Well-written book. Quite interesting. As normal for a Weber book, it is wordy and has a lot of conversations and maybe filler. If you like Weber's books, you'll like this one (as long as you aren't looking for space battles).