Leodan Akaran, ruler of the Known World, has inherited generations of apparent peace and prosperity, won ages ago by his ancestors. A widower of high intelligence, he presides over an empire called Acacia, after the idyllic island from which he rules. He dotes on his four children and hides from them the dark realities of traffic in drugs and human lives on which their prosperity depends. He hopes that he might change this, but powerful forces stand in his way. And then a deadly assassin sent from a race called the Mein, exiled long ago to an ice-locked stronghold in the frozen north, strikes at Leodan in the heart of Acacia while they unleash surprise attacks across the empire. On his deathbed, Leodan puts into play a plan to allow his children to escape, each to their separate destiny. And so his children begin a quest to avenge their father's death and restore the Acacian empire—this time on the basis of universal freedom.

Several years have passed since the demise of Hanish Mein. Corinn Akaran rules with an iron grip on the Known World's many races. She hones her skills in sorcery by studying The Song of Elenet and she dotes on her young son, Aaden—Hanish's child—raising him to be her successor. Mena Akaran, still the warrior princess she became fighting the eagle goddess Maeben, has been battling the monsters released by the Santoth's corrupted magic. In her hunt she discovers a creature wholly unexpected, one that awakens emotions in her she has long suppressed. And Dariel Akaran, once a brigand of the Outer Isles, has devoted his labors to rebuilding the ravaged empire brick by brick. Each of the Akaran royals is finding his or her way in the postwar world. But the queen's peace is difficult to maintain, and things are about to change. When the league brings news of upheavals in the Other Lands, Corinn sends Dariel across the Gray Slopes as her emissary. From the moment he sets foot on that distant continent, he finds a chaotic swirl of treachery, ancient grudges, intrigue, and exoticism. He comes face-to-face with the slaves his empire has long sold into bondage. His arrival ignites a firestorm that once more puts the Known World in threat of invasion. A massive invasion. One that dwarfs anything the Akarans have yet faced...

With the first two books in the Acacia Trilogy, Acacia and The Other Lands, David Anthony Durham created a vast and engrossing canvas of a world in turmoil, and of the surviving children of a royal dynasty on quests to realize their fates—and perhaps right ancient wrongs once and for all. As The Sacred Band begins, one of them, Queen Corinn, bestrides the world with her mastery of spells found in "The Song of Elenet". Her younger brother, Dariel, becomes a mythic figure in the Other Lands, while her sister Mena travels to the far north to confront an invasion from a brutal race intent on conquering the Known World. Their separate trajectories will converge in tumultuous battles, all rendered with vivid detail and in heroic scale.