The Sworn (The Fallen Kings Cycle)

As plague and famine scourge the Winter Kingdoms, a vast invasion force is mustering from beyond the Northern Sea. And at its heart, a dark spirit mage wields the blood magic of ancient, vanquished gods. Summoner-King Martris Drayke must attempt to meet this great threat, gathering an army from a country ravaged by civil war. And neighbouring lands reel toward anarchy while plague decimates their leaders. Drayke must seek new allies from among the living - and the dead - as an untested generation of rulers face their first battle.