The Awakening. The Sleeping King Trilogy, #1

When the fortress city of Greykeep falls to Maltherion's Deathless Legion, young scholar Kaelen Vross discovers an ancient prophecy hidden in forbidden texts. The legendary Aregor the Uniter isn't dead - he sleeps beneath Silverwatch Hill, waiting to rise again when the world needs him most. But waking a king who once united the realm through blood and conquest comes with a terrible price. As Kaelen assembles an unlikely fellowship - a battle-hardened commander, an elven ranger, a dwarf historian, and a street thief with unexpected destiny - they must face an impossible question: Is unleashing one tyrant the only way to stop another?The dead are marching.
The kingdoms are falling. And the cure might be worse than the disease.