The King's Sword (The Unsung, #1)

The commander who held David's kingdom together and paid for every victory in blood.

Joab son of Zeruiah rises from a highland war-band to commander of Israel's army under his uncle David. He wins the throne's wars, settles rivals the kingdom cannot absorb, and does the bloody work the king needs but will not own. He returns a banished prince, kills that prince in a tree to save the crown, rebukes a grieving king into public duty, and carves his way back to command when a softer man is set over him. In old age he backs the wrong heir. On Solomon's order he dies with his hands on the horns of the altar. He was the hard man the kingdom required, spent at last by the peace he made possible.

The King's Sword is historical fiction grounded in the books of Samuel and Kings: a novel of loyalty without tenderness, competence without permission, and blood as policy. Book One of The Unsung.