Empress of All The Stars. The Empyrean Republic, #3

Millennia ago, the planet of Arcadia was wracked by a bitter civil war. The losing Cadian Lords, rather than submit to the pro-Republic First Lord, fled into hyperspace with their followers. Their convoy crashed on a distant world and fell into anarchy. Centuries later, the Cadian Lords wage seemingly endless Resource Wars over control of their system's natural resources. Political scheming and constant raiding on far-flung shipping routes have prevented outright warfare from consuming the Freeholds' tenuous grips on civilization.
But now one House and its ambitious ruler have gained possession of ancient technology which might offer an edge over the other Houses. Yvonne Thibeau is willing to start a full-scale war to gain her goals, risking the very civilization she wishes to rule. The other Houses must put aside their differences and unite.or else the Cadian Freeholds will perish.