After centuries of stasis, the island kingdom of Charis began to defy the edicts of the Church of God Awaiting - egged on, some say, by the mysterious warrior-monk Merlin Athawes. Now, in the wars and intrigues that have cascaded from Charis's declaration of independence, the populous Republic of Siddermark is sliding into chaos...

This is book 6 in the Safehold saga which outlines more fascinating military technological innovations in the context of a science fiction historical drama! Sounds a strange mix, but the premise is simple - if you were able to influence weapon development during the 17th century which inventions would you have introduced to give your chosen nation the technological edge?