The Honor of the Queen by David Weber (Honor Harrington 2)

This time Honor goes to the planet Grayson with a diplomatic mission. Planet Grayson has an interesting history, it was one of the first settled worlds in the sector. It was settled by religious fanatics that wanted to leave all the infidels and technology behind. So they went 500 light years without knowing what they would find. And they found a beautiful planet that disappointed their wish to live without technology. Grayson is much denser than earth, with more heavy metals. Even the dust is dangerous to unprotected humans. To start with their society was male dominated and become even more so when survival forced the women to hatch as many children as they could for the colony’s survival.

The society on Grayson soon split in two. One Faithful to the original and one practical and numerous. Eventually it went to war, with the faitful loosing but not before they build a doomsday weapon that forced a compromise. The Faithful got Masada, a world they could reach with their current level of technology.

The Faithful on Masada has been plotting their revenge on Grayson for centuries and now they are ready to strike, with the help of The Republic of Haven. Against them are Grayson with their bigoted view of women and Honor Harrington’s out gunned task force.